Coming in late here. Giving this comment without judgement of you or her - just the basics which you will require to make a decision.
If you don't want to get past the fact that she's kissed a couple of toads, then end things today. Staying with a girl who you don't trust or respect is just a waste of time for both of you.
If you want to stay together, you will have to learn to accept her past. And remember that our pasts - the good and the bad - is what we learn from and what makes us who we are today.
these are your only two options. She cannot change her past - therefore you have to change your attitude or leave. It's all up to you.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.