Mother-in-law (81) Is Getting More Than Forgetful. Need Direction On Options. Texas

My MIL is having pretty severe memory issues. She is late on bills and missing doctor appointments and surgery. We have tried the last 5 years to get her to do medical directives and will, but she freaks out and says she isn’t dieing and doesn’t need to do that yet. She does want to split everything three ways and we have gone as far as making all the docs and getting a notary but she backed out last minute.

She has two sons, one is currently in prison the other is living off of her and stay rent free in a trailer she bought, he also constantly gets money from her. Her grandchildren are constantly getting money from her also. She is depleting her retirement quickly and I don’t think she realizes she is giving away so much money to her own detriment.

My wife and I are pretty well off and do not need anything she has but we are worried without a will or medical directives the two sons are going to do something awful.

What can we do? Can we have her declared mentally not capable and take over her bills to make sure she keeps her house and get involved with her doctors to make sure she makes appointments. We are also worried she is going to mess up her medication.