Space is as much space as she seems to want. As she is the one who initiated this it is up to her to decide what she means. So dont call her or email her, only answer with brief friendly responses. As for college this is a little harder...if you see her then i think you should smile at least, and then if she comes over thats up to her.
Without knowing the girl its hard to say why exactly she wants this space and whether it has to do with being treated badly by her ex's, who knows?! But what you did say is that she had JUST ended a relationship when you got together.
She could of been the sort of girl to go from relationship to relationship with a gap to 'be alone with herself and learn who she really is' and now by the sounds of this book on co-dependancy she could be taking steps to figure out who she is on her own and become an independant and strong woman. This is obviously a good thing for her, so respect her and give her the space she wants so she has chance to miss you and therefore want you back xx
******* 7 Times World Champion Michael Schumacher - the ultimate sporting hero *******