My mother is of sound mind, sharp as a tack but will agree with anything my brother suggests. He put her into a nursing home and now is selling her house. He has an offer on the house, she has not seen the offer, but he is going to sell it, she has not signed any of the paperwork. Is it legal for him to be able to sell her house, sign it away?
Momma - please re-read Maggie's & JessieBelle spot-on posts.
About selling the house, brother probably quickly realized that mom not ever going home. He was not interested in spending $ & time each month to maintain property as DPOA this is within his responsibility. You have your own home, so not a factor in this. Brother made a desisive action to cut losses from the start. He sounds very pragmatic. If house sold quickly, I'd bet it was priced to sell.
What does this facility cost? 10K? 14K? Private pay costs for NH easily 100K a year. If mom was in good health (even with early dementia) before the fall, & gets great care, she could go a couple of years even if bedfast.....costs will add up. If you were involved in moms life, you should have a firm $ on her assets, income and then add in the amount of the house sale...how much does it add up to? ask the facility what their rates are. Then do the math.
About the 2nd day & your SIL authorizing placement...what probably happened is that the first day mom was given a care plan evaluation that determined she needed 24/7 skilled care. Your brother as DPOA was told this and his wife was there to help him get whatever done.
You will not be able to get guardianship if your mom is still competent. However, if your mother wishes to chsnge her poa to you, she can do that.
I suspect that there's something missing, and that's a conversation berween you, your brother and mom's doctors. People can be "sharp as a tack" and still have dementia, i.e., not be able to reason sny longer. The fact that your mom agrees with whoever is in the room is a clue to that. I encourage you you to start a nonadversarial conversation with your brother about what is best for your mom.
I applaud your positive attitude of "always room for one more", but i think that you need to closely examine what mom's needs are at this time and what they are likely to be in the future. Just to note, your sister in law would not be able to "sign mom up" for long term nh care if she wasn't medically in need of that, at least not where I live.
Things with older people can change in the blink of an eye. I don't know the specifics here, but suspect that your brother did what he felt best. You are not cut off from your mother. You can still visit her in her new home and try to make it as home-like for her as possible. I know you will miss the old house, but things do change as our parents get older.
If her POA to him allows real estate transactions, and if the title company is okay with the POA, he can sell her home. If her home is in a land trust and a letter of direction is signed by the trustee or trustee's power of attorney, he can sell her home.
You alone are not capable of caring for someone around the clock. It took her to fall for your brother to realize this. If you want what's best for your mom, step back and cooperate.