Bisexuality Support Group
Bisexuality is a sexual orientation which refers to the aesthetic, romantic, and/or sexual attraction of individuals to other individuals of both their own and the opposite gender or sex. Most bisexuals are not equally attracted to men and women, and may even shift between states of finding either sex exclusively attractive over the course of time.
However, if you feel she is incapable of this change or if you honestly feel deep down that you need to be single or non-committed right now, then do listen to your heart HUG
I think that as long as someone doesn't cheat on me they deserve a second chance--especially if the love is still there. It sounds like she DID make a mistake or two or three haha and now wants to make that up to you, change for the better as a person, and grow in terms of her maturity/ability to have relationships. Who knows! Letting her in might teach you more than you think too :)
I'm here if you need to talk any time !