Mother asking to vacant the house

I have been living in my mothers house since my childhood. After the death of my father, my sister came to same city as mine. she is playing divide and rule policy to get my mothers attention and separate me and my mother so that me and my family can vacant the house and go away. Fights between my wife and my mother have increased that now my mother have asked us to vacant and go away. I have been living in this house since my birth and my wife and kids are living in this house since last 22 years. The will is under my name but now she is threatening to give the house to her daughter instead of me. She have started going to lawyers and spending all the time with her daughter. We tried to convince my mother that her daughter is just trying to build the conflict in the family but, she is not ready to listen to us. I am a cancer patient!! Her daughter never visited me in the hospital in all the 8 chemotherapies and later my mother expect us to go to her house and talk to her even though her daughter has never supported us. But when her daughter got ill midnight due to blood pressure, MY MOTHER asked me to wake up and drive midnight to her daughter's home just to see her. She knew I shouldn't got o her house because she have dogs and I am not allowed to go near dogs to due threat to infections. I don't understand how to deal with all this. Its been 5 months me and my mother are not speaking but living in the same house on different floors.