Answer: While I understand your feelings, I do not believe they are appropriate. You need to accept her for who she is, and what she has done, not pretend or wish she was someone else. If you cannot accept her prior sexual experiences now, things will not likely get any better once you are married. If it is important for you to marry a woman who has not had sex with anyone else, you may want to reconsider marrying her.
You also need to ask yourself, why is it okay for you to have sexual contact with her prior to marriage, but it was not okay for her prior partners? Why is it okay for you but not her?
Virginity is a spiritual attribute, not a physical one. Your girlfriend is not denying you anything, as a result of having past sexual experiences. While male and female virginity is becoming more popular, chances are that the women you meet daily have already had sexual contact with one or more partners. This means if you are going to limit your prospective partners to only those who have never had sexual contact with anther person, your choices will be greatly reduced, especially as you become older.