I stole from my elderly mother in law three years ago. I have been paying her back every month. She passed away two months ago. What can happen?

I was caregiver for my mother in law that lived with us. I got into gambling. I stole money from her thinking I could win it back. It is the most horrible thing and I feel awful. She didn’t want to file charges as long as I paid her back. I have been paying her every month. I am a third of the way paid off. She passed away two months ago. I have since started making the payments to my ex husband since her death. He is always saying he is going to file charges since I got a new boyfriend. This has been saying this off and on for nine months. His sister, who is in charge of the estate, says she doesn’t want to file charges because I have been paying it back. What should I do at this point?