Glory is presumably a friend of Sara's because in some episodes they hang out together. They don't seem particularly close and they may have met through class but after Sara visited Glory in the hospital she feels a bit closer to her. The two are not close after Julie's leave since later on the connection between the two is never really explored. Glory is also never given a last name (I think, correct me if I'm wrong) though she does become somewhat of a major character towards the end of the second arc of the comic books we see relatively little of her before that.
Glory seems like your average high school girl who have parents who clearly worry about her. When the serial rapist and murderer Mr.Gone comes into town Glory's father gives her a knife in order to protect herself which she rather ungracefully wields around with her sweetheart, Tommy. While in the laundry mat together, Tommy leaves to get food and drinks for the two of them. During that time Mr.Gone enters and rapes Glory and brutalizes her as well. She is left in mortal fear of the world and spends much time recovering in a hospital and being treated for wounds both physchial and psycological.
While she admits that everything makes her feel nervous still she eventually learns to move on in her life until the day that Mr.Gone shows up at her door once again begging her forgiveness. They have weekly sessions together where she screams and yells and beats him up for the horror and pain she's caused in his life but eventually she is able to come to terms with it and they become strangely friendly. This is all we know of Glory but her life is a strange one, unwittingly changed by only 10 or 15 minutes as a teenager in a laundry mat.