How do I get my mother-in-law away from my sister-in-law, not safe for anymore?

My mother in law has been with Eve(sister in law) for the past 4 years and Eve has been taking care of her all by her self. Well Iget a call from Eve asking me to come to her house right a way she lives about 2 hours away from me,she needs my help so I drop everything and go I left that night. I have a husband and animals to take care of but they will manage.I get there and mom looks good and well taken care of.She tells me that she is being evicted ,so I check out her paper work, and she isn't being evicted but being is being asked to leave 9 there was a problems with some cats she had been feeding and had been asked not to.As we were packing her things she asked me if I wanted to go to the store with her and I said we can't both go, what about mom she said she will be fine will be right back, then i notice in her hand was a lock , I asked whats that for she said i lock the door so no one can get in while im away.And she was going to lock it from the out side of the door I told her you can't lock mom in here and leave.She said its OK mom doesn't get up or anything.I told her it's ok I'll wait her with mom and she left.I should probably tell you she has dementia and Alzheimer.when she returned I explained to her that she cant do that it is against the law and very dangerous. She told me that a police officer that she knew said it was alright if she wasn't going to be to long.Long story short she had no place to go with mom so offered my home for them to stay tell they found another place and we had planned that she would move closer to me so i could help with mom. we get to my house( while I was gone my husband did lots of work to make assessable for mom.) changed rooms around and stuff like that worked his butt off to get it ready for them. Two weeks go by and it's been hell with her good enough and she has this thing that my house isn't safe.By this time i think she loosing her mind.I make moms bed and she takes it apart and remakes it.She won't let me help her with mom. I tried put everything we need when getting up in the morn all organized in the area that we needed it and the next day can't find anything she rearranged it all. our mom is incontinent so she has to be cleaned and changed when she gets up.Anyway so she says mom has a uti and needs to go to the hospital at this time I had had enough of her crap and was no longer willing to help her she wasn't letting help anyway,so she takes her to the hospital and she was right UTI and mom was discharged the next day but i didin't know this and two weeks go by and my mom still not home.So i call my daughter to come and take me to the hospital to find out whats going on.Come to find out eve had been telling the people at the hospital that mo has no where to go,and that eve is trying get her to go to rehab place for therapy.Mom has no insurance at that time but they were working on getting her insurance.Well i really didn't know what was going on my sister in law eve had told them that my place wasn't safe and that i had drug deals going on at my house (which was not the case) By this time I had had enough and told them that i will take care of my mother but my sister in law was not welcome at my house any longer. They wanted to send some one out for a home check which was fine,but eve said some more crazy stuff and had them keep mom in hospital for two more nights she has power of attorney,so there wasn't much i could do.Then the hospital release her to eve a she has no where to go because she wont leave mom with me, h*ll that's her meal ticket. So now we don't know were the h*ll she is the last we heard is that she has mom in a two bedroom office building with no bathroom that her church helped her get. Mean while the hospital is know concern about mom well being but now we don't know were she is. What do we have to do to get her to safety.