I’m genuinely worried about mom, and my house. What should I do?

This is a lot, but here is the situation. In September 2017 my father-in-law died of lung cancer. My mother-in-law started drinking a TON and showing signs she wasn’t going to be able to care for herself. I helped her figure out the financials, social security, retirement, etc., and got her bills set up on auto pay. We ultimately decided to move her in with us because basically she was going to die from drinking if we didn’t. The market was insane, we had to get rid of her RV, which we did by getting a toy hauler and rolling 10 grand into our loan, we sold her house and bought a house big enough to fit all of us. It’s in her name because at the time it just made sense (better rate, cheaper insurance, etc.) but I took money from my 401K to help buy it, and it was understood the house was ours, but we needed to do a will. My husband’s sister at the time was estranged. We moved in April 2018. A month later we had to call an ambulance because she couldn’t walk. She was drinking too much, and it was depleting her electrolytes significantly, but we didn’t really know because she was home alone a lot. His sister showed up while we were in the hospital and proceeded to complain about how messed up it was that CPS came and took her kid and her grandkids. My husband and I both had full time jobs, we had 4 kids at home and just realized we had agreed to life with an alcoholic. Fast forward a couple years, she’s still drinking, we’re still dealing but becoming worn down. She’s verbally abusive at times and openly hates my youngest because her quickly encroaching dementia has displaced years of sibling rivalry on my child, as she was a middle kid and hated the unfair to treatment she got because her younger sister was the baby. Sister-in-law pops up, supposedly newly “saved” (she’s been an addict with mental health issues and CPS involvement basically her entire adult life), but she was trying and if it was real, it’d be nice to have a break or at least validation! We help sister get a job (she’s like 44 and hasn’t had one since she was 19, is on housing and social security for mental illness) and help her start the process to get visits with her son. In 2021 Mom had apparently gotten involved in some credit card thing and Chase said she owed money. I asked an attorney who made a good point, at her age she didn’t really need credit, but because of her health and her credit issue, the money just sitting in her bank accounts needed to go. We sat her down, she chose to give each kid half because it was the inheritance anyway. I came up with the idea to take her and the family to Disneyworld to make some memories and so mom could enjoy the money too, after all it was hers! So we go, most of the money is spent on the vacation, sister spent a good chunk on attorney fees, we bought a 10-passenger van for sports and transportation for the whole family. We got back and mom asked me to just handle her finances from then on, (at her yearly Medicare check she was very obviously suffering from dementia). Shortly after my husband lost his biggest account and we were struggling. I talked to mom, and she said do what we had to. Over the next year I paid the bills with money from my job and mom’s deposits (prior everything was split; she only paid the mortgage) Sister knew and kept asking for money but wasn’t helping with mom’s care with any kind of regularity. Sister gets bariatric surgery in January and doesn’t go back to work, gets in trouble for continuing housing, is going to move in with father-in-law, and while we are gone on a sport’s weekend, she takes mom and gets POA, takes over her bank account and tells us they are selling the house. She says mom is terrified of us and told the family that we were responsible for the Chase thing and that we took her savings (leaving out that she got part of that also). Oddly the whole family is siding with sister, we aren’t allowed to see or talk to her. I’m genuinely worried about mom, and my house.