A couple of items:
1. What defines success?
Relationships most probably will fail(this isn't our parents or grandparents generation where it lasted forever). But that doesn't define it as successful or not. Wether it lasts 1 year or 20 years.....how was it? were you both happy? satisfied? Did you share experiences that you would only want to share with that person at that moment? Etc. Knowing that and the relationship will most likely be finite, will guarantee it is a "success." Wether you have 1, 2, 5, or 20 such relations in your lifetime without going nuclear on the other, you have been successful and enjoyed the fruits of life.
2. What other relationship is more honest?
You know what she has done in desperate times(wether it be once to pay a bill or a lifetime) and she knows the kind of places you have frequented and the activities you partook. With that out of the way, no need to act saintly or keep up appearances. Of course, still be a gentleman and leave it at that. Acknowledge once and never discuss it again if you both decide to move forward in a committed relationship. No need to make her feel(or remind) her what she did.
And the same for you. Think about, if a gringa knew you inhabited such places, you would never hear the end of it
Mi dos centavos on a popular & topical subject.