My younger half-sister moved in with my mother when my step-father passed and since has controlled my mother. What are my options?

It has been known Jennifer, my little sister, would inherit her father's 50% of the $2m estate, but I recently learned she had the entire estate transferred to her and her husband solely in 2021. I was estranged from the family for 10 years and my mother and I reconnected 2 1/2 yrs. ago. Since then, I have spent a lot of time with her. She is 80 but still very spry and it was wonderful to have her stand up for me against my toxic siblings, finally. The estate is 5 acres and I would often stay for a week as my resort I live at requires 3 weeks in and 1 week out. I would stay in my RV on the opposite side of the property and rarely go in the main house when they were home. Throughout our relationship I have had the husband whispering adverse comments in my mother’s ear, complaining about all I do. I am a previous contractor and do projects around the house my mother wants done. Jake, the husband who has been in the family 3 years and best friend of my sister's ex-husband, has no right to be interfering in my relationship with my mom. I have asked him numerous times to just come talk to me if he has an issue because it just stresses my mom out, but it continues. He goes as far as standing in the middle of her room as we are talking acting as if he is on his cell phone and not realizing he is in the room, full focus on the conversation or website he is on. I see right through him and have tried to talk to my sister but she does nothing. My mother feels as though it is her responsibility to fix whatever his "concerns" are which just stress her out. Jake and Jennifer are constantly involving her in every instance they can speak ill of me, often leaving out the part where their actions are questionable or wrong.

A few months ago I finally blew up and told Jake what a punk he is and told him I was going to share with Jennifer what he had done 4 months prior that I had been protecting him. Jennifer's bday we went on a wine tasting fun bus and everyone was drinking, I don't drink but Jake came and sat by me and grabbed the back of my neck and pushed my face into his crotch suggesting oral sex. That night I discussed this with a person we both know and I told Jennifer I could prove it. The response was to shut me out of my mom's life and lock all the gates that I would enter. My mother was sent to me to collect my remote control for the gates and I was told I had to have my mail rerouted. This was a month before my mother's 80th bday party which I was now uninvited to. I knew it was time to do something about the situation. I discussed with my other sister filing in court for undue influence and she told my mother, despite her benefitting from this. My mother wouldn't speak to me or respond to my texts. May 18th I was suspended from the resort I live at unexpectedly and I had just spent $350 for my week out which puts a great strain on me. My suspension was for 30 days and my truck, not completely registered as I am waiting for a hearing on the use tax of 3k, which leaves me without a plate. I don't drive the truck if I'm not pulling my RV (afraid of being towed). I had 2 bad tires and my RV was immobile. I texted my mother and explained the situation I was in and asked if I could please come there to get my tires fixed. She initially said she would pay for a campground, but I could not come there. A few hours later, Jennifer heard and my mother would not even return my text so, the help with somewhere to stay was no longer an offer. I explained I could lose everything, all my food I had just bought for the three weeks is going to spoil, I can't move and had no gas for the generator, 2 weeks no response despite my pleading and my being afraid and alone. When everyone went to work and she was alone she texted me and offered help, she sent $100 then 2 days later she sent $500 for my registration but nothing since. I thanked her and said this wasn't her problem, but I just wanted to be safe. No response. Any suggestions?