My sister tells my mom what she can or cannot talk about. She repeats constantly what she wants my mom to remember or scares her by asking her if she really wants her or her daughter to have to go to court because that's what will happen if she says anything. She is misusing her money and tricked her into putting my nieces name on the title to her car. They took moms name off the title so I won't get it even though mom stated it was to go to me. She won't let me see mom at her house and has lied to obtain a restraining order against me which was revoked. I am not innocent but I would never do these things to mom. Please help me.
I'm sorry that you are so worried about your mother and I understand that you want to protect her. But I have to tell you that, from the point of view of a full time carer, you do come across as someone who makes allegations without taking into account the realities of caregiving. Coaches her to remember? I expect she does. What would you do? Leave it to chance and your mother's confusion?
You also say that your sister uses going to court as a threat to scare your mother. But then you say you're going for guardianship? So how are you planning to do that without going to court? Or is going to court only scary if your sister does it?
Besides giving 'your' car to your niece - but presumably thereby keeping it available for transporting your mother, by the way - what is the inexcusable thing that your sister has done?
For your mother's sake, I hope beyond hope that you are mistaken in your allegations.
To be blunt, what would help your mother is a radical improvement in the relationship between you and your sister. You are both her daughters. Hurt to either of you hurts her. So this applies to both of you: sort yourselves out and stop playing silly buggers.
If mom is being mistreated you call APS and/or an elder care attorney. Are you going to be the caregiver? Is your sister burned out? Sounds as though your sister needs to understand dementia better. Perhaps mom needs professional care in the not too distant future.