Any possible recourse?

I had the pleasure of meeting and helping take care of my boyfriend's mother during the final few months. She had COPD rheumatoid arthritis which caused her to be in crippling pain continuously. His sister was her full-time "caregiver". But she was so lazy and took terrible care of her in the sanitary area so bad she had reoccurring uti's to which a couple became septic. She was deteriorating rapidly before our eyes. His mother was am amazing woman but she did not want her son's girlfriend to take her to the bathroom or give her a shower even though I wouldn't have even thought twice about it. Her daughter was mixing her medications and trying to get her put in a LTF. I can't be paranoid to say I feel his sister was helping that situation end sooner. She was clearly annoyed having to take care of her mother even though she has done nothing but sponge off her and her father their entire life. And it has definitely not changed after death. She signed his mother's name on a quit deed and had her best friend the notary sign it. She has passed now and 2 days later she recorded the deed, and had everything skip probate and is now trying to charge him rent to stay in his mother's mortgageless house and saying his kids can't stay here even though everyone knows those kids were her babies and what she really wanted was to leave the house to them. Not her son especially not her daughter.  She wanted it to be a forever home for her grandkids to always have a place to go. She has left him in the dark about everything. She got his dad to sign over POA to her bc all she cares about is getting her dad's vet check and pension because she hasn't worked in years and "she deserves it" and dad was the sole beneficiary of his mother's life insurance. I have already gotten the new POA signed and in my boyfriend's name and the one in his sister's name revoked. I will also get handwriting analysis done to prove the quit deed was forged by his sister. Like I said she filed a declaration of Domocile and disposition without administration. She now has her house, car, home full of beautiful possessions and their joint bank account. I'm not even sure if a will has been turned in although it wouldn't surprise me if she got rid of it if she didn't like the response because neither his father or him have recieved anything in regards to letting us to her even having a will his sister is the greediest person I have ever met. What she is doing is disgusting and must be stopped. I have very little funds and would like to know what my next steps should be.