What is the ruling concerning a girl who disobeyed her parents for the sake of a desire, even though her parents implored her to abandon this matter?

This question contains a generality. If the matter in which she disobeyed her parents was marriage without their consent, then if she married without her guardian's permission, her marriage is void and must be annulled, because the guardian is a condition for the validity of the marriage. If the matter is related to committing a sin, then she is sinful in two respects: first, her disobedience to her parents, which is a major sin, and second, her commission of this sin. What is obligatory upon her is to repent to Allah and to seek the pleasure of her parents.