Pauline is Pecola's mom, and her character allows us to see how cultural conceptions of beauty can play themselves out in a more benign, though still unfortunate, form than in Pecola's case.
Pauline's lame foot is a constant source of humiliation for her. Once she moves to Ohio, she must contend with regional and social class barriers to normative beauty that she had never imagined. Up north, Pauline's southern accent makes her stick out like a sore thumb, and her inability to keep up with the latest fashion takes its toll on her spirit as well. When Pauline loses herself in Hollywood films and styles her hair like Jean Harlow feel prettier, we see that not only were little girls influenced by white celebrity culture, but older black women as well.
Once she loses her tooth, Pauline's preoccupation with making herself beautiful is replaced with an obsession with being the perfect servant for the Fishers. In this affluent white household, Pauline gets to pretend that the Fisher kitchen is her kitchen, that the money she receives to buy their groceries is her money, and maybe even that their little white daughter is her daughter. Just like her daughter Pecola, Pauline creates an elaborate fantasy world that consumes her.