Well, being someone who has done that before, I'll try to clue you on what it means: She's not exactly content (this could mean anything from looks to affection to performance) with the guy she's sort of with at the moment, so she's shopping around for a better one. If she does not find a better one, then she'll stick with the "sort of" bf. At the same time, it could mean she's not so sure about where the "sort of" bf stands about their relationship. She hopes this dating stuff might make him a little more interested in her. However, she tries to secure her position in case the "sort of" relationship amounts to nothing.
I hope that helps and makes sense. 🙂