Character Analysis
Mother Figure
Mam is the black woman who works for Victor's parents, but she's more of a mother figure to him than a babysitter. She's always there to support and love him, and he grows up thinking of her as a family member or best friend:
Mam came to Memphis from Mississippi when I was five to live with us and help take care of me and one thing's for sure. I wouldn't have made it this far without her. (1.11)
Mam doesn't act like just an employee, then; she cares for Victor like he's family, even going so far as to put herself in danger's way to protect him. When Ara T steals Victor's knife and money, she confronts him, though it ultimately means that Ara T beats her up. Mam will do anything for Victor because she loves him. She's willing to protect him at any cost… and he feels the same way about her. Which is good, since in the name of helping Victor, Mam winds up dangling in the air by her throat with Ara T's hands wrapped around her neck, and Victor's the one who saves her. Phew.
Different Strokes
Being around Mam introduces Victor to a side of the world that he's not familiar with. Growing up in the segregated South as a white boy, he doesn't often think of race issues. But when he spends time with Mam, Victor realizes that there are a lot of terrible rules that she has to follow—and that this is completely unfair:
Thinking about somebody hurting Mam and then remembering all the stupid rules that Mam had to live by just because of her color made going to sleep a hard job. (11.60)
Mam doesn't complain about her circumstances; it's simply through being exposed to life as she lives it that opens Victor's eyes to the way the world works and how it could be better. Victor might feel different due to his stutter, but in spending time with Mam, he sees how superficial differences really are. In rallying behind Mam, it seems Victor rallies behind himself a bit, too.
Imperfect Perfection
It's important to note that Mam, for all her feistiness on Victor's behalf, is depicted as happily raising someone else's child and making her way through a life governed by outright racism without resisting this system or responding to it with anger. The only real obligation Mam seems to feel is toward Victor—she risks her own well being more than once on his behalf—which reduces her to a sort of "happy servant" role instead of developing her as a complex character. As a black servant in the segregated South, Mam takes her place in a long tradition of 2D characters willing to do anything for the white people who employ them while generally accepting their own fate.