Should my mother sign a quitclaim deed over to her brother, and if she refuses to what will happen?

My grandmother recently ped away with no will. My mother's siblings have all signed over a quitclaim deed transfering the house over to the youngest brother for $1. My mom doesn't want to sign the deed. Instead, she wants the youngest brother to buy the house, and divide the monies equally between all of the siblings. What happens if my mom doesn't sign the deed? Can her brother continue to stay in the house and pay the remainder of the mortgage left on the house? None of the siblings have the money to take this to court. What will be the probable outcome?