Who is Bonnie Flannigan from Johnny Got His Gun and what is their importance?

Bonnie Flannigan is a Los Angeles prostitute and pickpocket, Flannigan is originally from Shale City, Colorado, where she was behind Joe Bonham in school. She lives in a bungalow court near his bakery, and wants to get together. He knows she is a prostitute and is sorry that a girl from Shale City has come to this. Flannigan is large, not cute, but good-natured, and full of life.