Character Analysis
Auntie is the classic martyr. She actually enjoys suffering because it means she gets to complain about her problems and show people how virtuous she is. The term "martyr complex" is a reference to the early Christians who suffered torture and execution for their beliefs, so it's no coincidence that Auntie is a Christian. She attends church . . . well, religiously, you might say, but she never invites anyone in the family to go with her. She likes going to church by herself so she can show off how devout she is—unlike the rest of her immoral, pagan family.
Auntie is a significant figure in Tayo's life, but not in a good way. She raises Tayo "to conceal the shame of her younger sister," who conceived Tayo with a white man while she was working as a prostitute (V.89). Sounds like a charitable thing to do, but remember—Auntie only does charitable things to remind everyone else how virtuous she is. She never lets Tayo forget that he's a charity case, and that he's not as good as her own pure-blooded Laguna son Rocky.
Auntie's treatment of Tayo as a child leads him to feel guilty and ashamed of being half white. In order to recover after the war, Tayo has to get over the shameful lessons Auntie taught him when he was young and learn to accept his own identity.