Any advice for a new caregiver?

Oh dear! This is going to take a huge toll on your life....oh yes. And...when it is finally all over...the price will continue the rest of your life!

This are the years of your highest wage potential. You not only lose the wages of these years...you lose the wage increases...you lose the years of experience in your job...you lose the retirement funds, you lose the social security benefits. Years from now you will realize you didn't just put your life on hold....to a real degree you sacrificed your entire future.

You do not get any "do overs" in this life. By the time you see how huge the price was for you..it is too late to undo the damage!

And...your marriage will likely suffer a great deal too. Tell you what...ask hubby to quit his job for years to do this...bet you flat out refuses! Know why? He knows what a lousy future it would mean

Then...when you get divorced (odds are not good...be realistic). You lose again. Hubby has his entire employment history and salary increases intact...you have no recent experience and no savings.

Ok...that was the lecture.

Here is the advice
DON'T

She could live for another 10 or twelve years.

You sound like a level headed young woman who thinks she may have been sold a pig in a poke. You have.

Why on earth would you give up employment to care single handedly for someone with a progressive illness that has no charted trajectory?

Dementia patients need three shifts of caregivers. Read through the threads here. Make an informed choice.

If nothing else, make sure you have a caregiving contract so that you are being paid out of her funds. No " oh, I'll leave you the house". Medicaid estate recovery will get the house unless she is
generationally wealthy.

"I feel like we're putting our own life on hold a bit. . . I'm quitting my full time job so I can provide her with 24/7 care, and I really feel like this will take a huge toll on my personal life and even my marriage. "

Read back over your own words and let the reality of these statements sink in.

You should hire other caregivers to help out otherwise your marriage will suffer - and most importantly - you will suffer. It doesn't matter how close or not close you are to the patient, caregiving is a major stress on the mind-body-spirit. Dementia alone is awful when it's progressing but the combination of diabetes and dementia is not a pretty picture. Poor blood sugar control will affect her mind, like causing extreme agitation, confusion, and urinary incontinence (which also are symptoms of dementia so you've got a double whammy here) My mother is now experiencing this as part of her decline. The poor blood sugar control just makes the dementia screaming worse. Every day I thank whoever invented ear plugs.

You have already moved into GM in laws house which is going to be more difficult for you to get out of.
If you had not already moved in I would definitely say "Don't do it"
You are not being a selfish brat you are being sensible thinking about the downsides before you gets sucked in too deep.
You will need three full time caregivers so no one works more than 8 hours. You will also need people to cover days off etc. Do not make the mistake of taking the night shift under any circumstances. You are newly married and that will be the time hubby is home and it is essential you spend that time with him.
I would also not recommend giving up your job either. A promise to leave you the house will be worthless when the absent relatives come out of the woodwork circling like a bunch of vultures.
I realize my answer is not warm and fuzzy but I do aplaud your decision to be prepared to take on this task. Do not make any promises you can not keep. Most people find the financial stress will also be great. If GMA had funds you would not have been tempted into this situation. So if medicaid comes into the picture the house will have to be sold to cover her expenses. There really is a lot to consider.

Most (all?) of the answers so far boil down to "Don't do this." I concur. But if you are going to do it, here are some points to consider.

1. Right from the beginning have a respite plan in place. You absolutely will not retain your sanity doing care 24/7/365. You have to have time off during the week, at weekends, and for vacations. This is critical. Without this considered seriously from the beginning you will crash and burn and probably your marriage will go up in flames too.
2. Get paid. If GM can afford to pay you market rates, great, that is what you should charge. But even if all she can afford is $50 a month out of her SS check, take it. It gives her the dignity of paying her own way, and it gives you a little something to remind you that what you are doing is worthy. Have a formal care agreement in place. It will be useful if she needs to apply for Medicaid.
3. Get paid now. Looking forward to an inheritance is not the same as getting paid.
4. Assuming GM doesn't have much more than her house and SS check, apply for Medicaid now. They do cover some in-home care, all deductibles on drugs, and have other benefits for a person still in the community. And if the time comes when GM needs a nursing home, the Medicaid coverage will already be in place. (Disregard this point if GM has lots of assests.)
5. Do NOT ever promise that you will never let GM go to a home. I didn't even promise my husband that. I promised I would never abandon him, I would keep him at home as long as that was the best option for his care, and I would always be his advocate. I repeat, do not promise she never will be placed in a care center of some kind. You never know how and how fast dementia will progress. It usually reaches a point where it can't be handled by family members at home.
6. If you are a professional, stay in touch with your industry. Attend the monthly professional association meetings. Mingle. Network. When asked where you work say, "I recently worked at XYZ. I'm taking time right now to care for my Grandmother, but I expect to be back in the workforce within a few years and I'm keeping current on developments in the field." Stephanie, is there any possibility of doing some work at home in your field?
7. Join a caregiver's support group. Ideally find one specifically for people caring for someone with dementia.
8. Maintain your own health. See the dentist on schedule. Get your flu vaccination. See your doctor on the same schedule you would have if you weren't working 24 hours a day. If new problems arise (depression comes to mind) get treatment!
9. That respite plan I talked about? That is not for grocery shopping and running errands. Use it to take a class in your field of work. Frequent date nights. A matinee movie or concert. Plan for respite and use it! (If Medicaid provides some caregiving hours, that can be used to provide your a little time off each week.)
10. Enjoy having this little old lady in your household! Create moments of joy for both of you. Do things with her up to her capability limit. Play cards -- even if it has to be Go Fish or Old Maid. Laugh at a funny old movie. Let her scrub vegetables while you prepare dinner. Get her to dictate a brief story of her life, type it up on the computer, and print it out. Read it together once in a while. Go out for root beer floats for breakfast. Visit a garden center and admire all the flowers. Your treats and outings don't have to be expensive -- they just have to joyful! Realize that if she were in a nursing home she would have opportunities for entertainment and activities a few times each day. You probably can't match that, but do consciously provide some pleasant stimulation.

I really think this is the wrong time in your life to be taking this on. This is your season for building your career and, if you decide to, starting a family. But if you are going to do it, also take care of yourself and build as much joy into this arrangement as you possibly can!

Who else is involved with your husbands grandmothers care? Do you take her to her dr appointments? Are you listed as a person that the drs can speak with? Do you have her DPOA? Does she have a DNR? If there is a promise of leaving you her home, do you have a copy of the will showing that or has a legal document been prepared? Perhaps you are being paid. What happens when you realize you can't go without sleep and need more help? Is there money to hire help? Are you in a position to even ask about these questions? At 91,regardless of how she is doing, you know that it could all change tonight? Right?
Do you know her A1C? What her medications do for her? What her diet should consist of? It's difficult to give you advice without knowing your position, your responsibilities and your expectations. Having asked all this (and believe me We could all ask many more questions) I wanted to add that
I did something similar. I was in my mid twenties when my husbands grandmother came to live with us. I had two small children. I think I only had her for about six months. She had been living with a family as a caretaker. She got sick and needing care herself, we offered her a home. I had met her a few times at holidays. She was very sweet and tiny and seemed really old to me. I think she was in her mid 80's. One day she started calling me by a DIL's name. She had had a stroke. My MIL and her sister decided she needed more care so she was placed in a NH. They were concerned she would be too much for me with my two small children. I remember my time with her with great affection. We called her "Little Mama".
I had a younger brother who was dying of cancer. He would come over And pick us all up and take us for a ride. It was so sweet. We were such a funny little group. He died at 19. She died a few years later.
She didn't have diabetes. She probably did have a touch of dementia. This was a long time ago so some of the details are fuzzy. Keep coming back to this site. You can learn a lot here and it can all work out but at 91 anything can happen. As sharp as a persons mind might be, the body wears out. Not many live to be much more than her age but some live to over 100. Do the best you can and know that you can change your mind. Don't spend her money without very good records. She may need Medicaid to pay for a NH and you wouldn't want her to be denied benefits because it looks like she gave all her money away. If she is going to be paying you, have a care contract drawn up that specifies what you will do for your payment. This will help protect both of you. She may know how to handle her finances today but not know tomorrow. Understand that although you could spend many years caring for her, she could be gone very soon, so your job (and home) could be very temporary.

Please don't give up your job. You need to take care of you too.
You are not a selfish brat at all and you are putting your life on hold, or worse - taking on an almost impossible task that will seriously negatively affect your life. Please rethink this and the care of grandma. Discuss other arrangements for her care with your new hub.

Where did this "selfish brat" thinking come from?

It looks to me like your husband and his grandmother has found free care in your quitting your full time work to care for her which does not sound fair.

Where are grandmother's children? Why aren't they helping in some fashion with her care?

I think that you need to have a heart to heart talk with your new husband about this and stand up for yourself.

What is in this for you? Nothing! You have no idea how all consuming this job is. It will suck the joy from your life & exhaust you. I would run away from that situation as fast as my legs would carry me!