Why is Mama most deserving of her dream?

Mama has certainly given up the most for the family to deserve her dream of a house with a yard and room for a garden.  For instance, in the opening scene of the play, Hansberry describes the apartment which Mama and Big Walter had picked out when they were first married.  It was never intended to hold the number of people it currently does, and Mama has had to deal with that disappointment in her life, among many others, like the death of her husband, who worked his whole life trying to keep the family above water.  Mama has also had to deal with the disappointment of her children.  Walter Lee take most of the play to learn what it really means to be a man and take care of his family, finally understanding that money is not the most important thing in the world.  And Beneatha is just as selfish as Walter Lee, without the extended family. She is the only member of the family (besides Travis) who doesn't work toward the family's life.  Instead, she spends money on her education without thought as to how that affects others.  And since Big Walter's death, Mama has taken on the role as the head of the household because Walter Lee cannot be trusted, which is why she made the down payment on the house in Clybourne Park in the first place.  So, ultimately, Mama is the most deserving of achieving her dream, though she risks it all in the end to hand over the reins to Walter Lee.