At the beginning of the novel, we see her as a classic Beta, one who is programmed and genetically modified to do her job well, to have a lot of shallow relationships with people, and to be fixated on activity and pleasure. However, it is through Bernard and John that her character is given depth. First of all, she goes out with the antisocial Bernard; this indicates possibly a level of maturity not found in her group of women. Then, when John comes onto the scene, we see her become completely turned upside down over him. She experiences, for the first time, real love and desire to be with someone, deeper than the shallow relationships she's had in the past. We see her struggle with those feelings and that change, and try to fit it into her realm of thinking.
John is the real force for her dynamic status; otherwise, she would have remained a flat, stereotypical character that is highly predictable because of her social class. John in fact does a lot of interesting things to the main characters of the novels; once he comes on the scene, he is a force that changes all of their lives. I hope that helped a bit; good luck!