POA for sale of property

My mother is 98 years and bedridden/immobile. Vision list. She has a house in Chennai. I am the only son and I hv 3 elder sisters. My mother made a settlement deed (az per Govt of Tamil Nadu rules allowing settlement of deed) in 2008. I am meeting all medical expenses of my mother. It is self acquired property. My mother's mother had this property and on her death my mom bequeathed this property being only daughter of my grandma and my mother didn't have brothers/sisters. My mom told me to sell house now and use for medical expenses. She can't go to registrar office now being immobile. She told me to make a POA in my favour and sell house and take proceeds. She doesn't want settlement deed to be cancelled. She said if sale takes place based on POA settlement deed will get cancelled automatically. She doesn't want gift deed or relinquishment deed but 9nly POA in my favour. She says don't go for release deed as they will attract high stamp duty whereas POA costs less.Can POA be the best option for sale of her property under her medical circumstances.