Well on of them has quite a bit of history and the two others were made for the chain gang.
The girl with purple hair is one of my earliest characters. Her name is Vikki Ramirez who's a bit of an angry tomboy and was previously a army mechanic. She can be found in this old picture of mine
The other two I refer to as Blondie and Pinkie. Blondie is a nervous wreck because the guard is always shouting at her and Pinkie the most happy-go-lucky out of the group.