In my humble opinion, it is very important to make the difference between the fundamental structure of some sexual sins (the libertarian values about the sexuality before he wedding and after the marriage) and *the human weakness concerning the temptation of flesh. The weakness of flesh between boy friend and girl friend is immoral and is sinful, it is not the ideal, of course, but the sexual doctrine of the total liberty is worst than the sexual weak, 5 times in the love, even if it is forcination. *The level and the degree are not the same.
If she was and stays, in doctrine and in praxis, a female liberterian about sex, I could understand your view, even if the catholicism is in favor of forgiveness.* You have right to want a honest girl, as wife and potential mother.
But in this case, it was only a weakness, during a moment. it is totally different.**
In conclusion, there is a saying that says *" the fact of entering into a marriage means to be capable to forgive the infidelity of the other, under special conditions. If you love your spouse, you need to be ready to forgive his sexual sins, otherwise you are not ready and it is not a conjugal love." *This saying is phrased with my own words.