Ask her directly. She may deny that she has done anything.
Be ready to give her proof.
Decide where to go from here. Is it love for both of you or just one?
For the record, nobody is out of anybody's league. Love doesn't care about where people are from and real love isn't concerned with whatever a person looks like.
One other thing, see a counselor to talk about this and get it off your chest, regardless of what the marriage outcome is.