When a woman commits fornication and marries her lover, is the sin of fornication removed?

Fornication is one of the enormities the sin of which is removed by repentance. It is not a condition for repentance that a fornicator marries his lover. Rather, repentance is by desisting from such an act, regretting having committed it, and resolving never to return to it again. God forgives whoever repents whether or not he marries his lover. Repentance is not bound to marriage even if decency demands protecting the woman with whom he has erred. If both of them repent and are suitable for each other, then it is preferable that they marry each other.

God the Almighty knows best.