Is it permissible to get involved and marry someone the family has rejected, knowing that the girl is not a virgin due to someone else and he is agreeable to the concealment?

Adultery is one of the gravest sins and indecencies. The male and female adulterers are in great peril unless they repent with sincere repentance.

Anyone who contemplates adultery must remember that Allah is observing him and will hold him accountable for his actions, and that the disgrace of the Hereafter is far greater than the disgrace of this world.

It is not permissible for a woman to form relationships with any man, due to the corruption that results from such actions. She must sever any such relationship immediately.

The condition for marriage is the guardian (wali). If the guardian obstructs the marriage, the matter can be taken to the courts to transfer guardianship or compel him to allow the marriage.

Fathers must fear Allah regarding their daughters and not prevent them from marrying a man of religion and good character.

If the man is of religion and good character, she can try to convince her parents or seek mediation from someone who can convince them. If he is not a man of religion, she must forget him and be patient until Allah facilitates for her a man of religion and good character.