These are the things that reveal themselves...in my experience. It's sometimes in hindsight that I get and understand the purpose of what you are talking about. It's even in the negative experiences that I have learned something - in fact, that is the greatest growth I get in is situations where things don't turn out the way I expect or want them...and there is the problem...my expectations and wants, as opposed to just going with God's will and listening to that conscious contact voice we all have.
It's not my place to say whether or not this girl needs to be in your life, or should be. That's up to you. But I sometimes realize that when I get into something that disturbs me in some way, I certainly have to look at myself as to why I am being disturbed, and then determine if it adds to my life and sobriety, or if it doesn't.
I wish you the best!