Mama scolds her for acting like the rest of the world. Looking down on him as a colored man doing low pay jobs to support them, and no one wants to claim that they know that poor sod. Mama tells Bennie not to write his epitaph like the outside world because she doesn't have the privilege, because she's just like him. Mama isn't trying to remind Bennie that she suffers the same ordeals, but perhaps if she was the man of the family she might do the same. Bennie herself would try to provide for them, and Walter's actions were meant out of kindness, and the least Bennie could do is to be with him in his time of need. Maybe Bennie's attempts at being a doctor were partly out of love for her family to help provide for them, not out of pity or personal honor, but for unity. It's not the characters that make the family struggle but mostly the conditions their forced to endure. Socially, they are shunned for being Negroes. When Mr. Lindner bribes the family to move out, the idea threatens to tear the family apart. The idea is at first easily denied because of the money they have to support themselves (A Raisin in the Sun, 892). However, when Walter loses the money, Mr. Lindner's offer appeals to him (A Raisin in the Sun, 909). The family becomes shocked and tries to support him in his decision, but Walter realizes the importance of family and he turns Lindner away. .
However, the climactic theme of the story is Walter's selling out point. A typical reader would want to hate Walter for using the money to start up a liquor store, but then it's realized that he was only doing it for his family (A Raisin in the Sun, 896-897). When Walter gave the money away, he gave away the family's future too. Beneatha wasn't securely in school anymore, Travis would have to keep sleeping in the living room, and there isn't money for Ruth's baby. Not only did that affect their futures, but it hurt Mama as well. In a way, Walter gave away their memories and values.
