If she is your gf, I am 85% sure it is because of the feeling
she and you give to each other purely based on emotional and
spirtual basis eh? 
So there is nothing to with her whether she is a virgin,
non-virgin, raped, etc. And since he has nothing to with that - you
MUST accept her for who she is and love & treasure her more
because of her sorry plight. If you were to mind and get bothered
over it - you are NO better than the guy who raped her because YOU
are the one who reminded her about her past and actually make her
feel that she is worthless because of it. 
My tudi (Disciple)'s ex was a victim of such case. She was inferior
and deep within her, she suffered psychological problem as she
feels that she wasn't worthy of him. My tudi didn't mind, but the
shadow kept haunting her, until eventually, she made the decision
to leave him - which of course causes much distress and sorrow to
both parties.
A rape victim is needs more than just love in generally - a victim
themselves, their image of men & love is tanished. If you truly
love her - You must:
I) Guide her, lead her and enlighten her that past experience will
serve to build her.
II) Treasure and love her equal or more - she is no lesser than any
of your ex.
You must prepare to run that extra mile in the relationship and as
always, are you willing to make that extra mile?
Cheers
