what are my mothers rights on the husband property ?need legal suggest

I'm 27 years old, My mother married my father in the year 1992, he passed away when i was in her womb.then there was no connection between them and their family for these many years.she was living with my grandfather they were the one who is looking after us.they had no intension to support us neither we demanded them. Now last week one of their relations came and asked my mom to sign to sell one property because her name was also part of that property. though we haven't expected any money, but i feel my mom deserved it for all the pain she was going through .she didn't even demand to raise me, or they were willing to give during tough times, as he was the one who contributed more to their family, I wanted her rights to be protected, wanted to know what are the rights she can exercise and get paid for the thought times she has been through. They came to us only because the property has to be sold only with my mother's signature.else they would not have approached us.