Dad Is Selling Home That My Mom Stayed In After The Divorce. Her Name Isn't On The Deed Or Mortgage, But She's Put A Lot Of Work Into To It. Is She Entitled To Anything From The Sale?

Location: New York State

My dad is on the deed and mortgage of my childhood home, sold to him in 1999 a few days before I was born. My dad and mom were married at the time, but she isn't on any paperwork. The house is ~$20k from being fully paid off. In ~2009, my parents divorced, and because my mom would remain the primary caregiver (as she doesn't work/receives disability), my mom and my brother and I stayed in the house, and dad moved to an apartment nearby. I assume he continued making mortgage payments during this time. A lease agreement was never drawn up, theory divorce was quite clean. Not a lot of bad blood.

My mom remarried in 2010 to step dad. Together, they had and continue to raise my half siblings in this house. Stepdad made and continues to give dad checks every month, I assume in the amount of the mortgage payment. Step dad is a bit of a contractor, and has done many projects to the house to make updates, mak things nicer, maintain, etc. The kitchen is totally redone, they added a bedroom, there's a new back deck and front porch, a new pool deck, the list goes on. He did a lot of work. Place is pretty nice compared to other homes in the area.

Short question is, now that dad wants to sell, is my mom/step dad entitled to anything for the work they put in?

Extended bonus content for those who may find it relevant:

Dad sent a third party assessor into the house, with mom's permission, to look around and get an idea of the work that needs to be done. Dad tells me that the assessor said the house is in disarray and needs X thousands of dollars of work, namely a new roof. That dad won't get much for the sale of the house.

My mom and I believe he is bluffing. Yes, the roof needs to be redone, but I recently bought a house in the same area, and we keep up with housing prices. Dad is making it sound like he is lucky to be rid of the place, but we've seen homes in terrible condition here go for a pretty ok amount.

What do you think about this situation?