My 61 year old mom and 72 year old dad are taking care of my 94 year old granny who has dementia. my ganny also can hardly hear and is almost deaf. so communciacting with her is very difficult(even with actions). She keeps nagging my mom with a question - 'has rice been cooked?' And even if the rice is cooked she keeps going and trying to make it herself and opening vessels, trying to put on the gas etc, which she actually cannot do. She leaves the taps open, hides her things( and with that my parents things as well), and then goes about on a hunting spree and messes the whole house looking for her things. My mom has to bathe and dress her too. My mother is suffering from oestoporosis herself. They hardly have a moment to relax as she is constantly nagging them.
To learn more about this terrible disease click on the link below and scroll down to the articles. Many are about Alzheimer which is a form of dementia, so the articles will still be very helpful to both you and your parents.
There might be a time where your parents will need to hire a professional caregiver who is familiar with dementia, or a time where you parents might need to place your grandmother into a continuing care facility for her own safety and well being where there are 3 shifts of caregivers watching over her.
https://www.agingcare.com/Alzheimers-Dementia
Given her parents' ages and health conditions, she needs to explore care options for granny outside the home. The dementia related conditions will only worsen, placing a greater burden on her parents as they age.
This is a case where caring for one's parents is misguided. Granny needs skilled care and her parents need relief.
We don't know where Jenmen lives or her family's financial situation. But she needs to find someone can advise her about her family's options for granny's care outside the home.
Losing one's parents brings so much pain. So I would do everything I could to extend their lives. Being a full-time caregiver is guaranteed to shorten their lives.
Best wishes to you and your family!!!