What is the ruling on a marriage concluded without the knowledge of the family, and does a divorce enacted under duress take effect, and what must the questioner do to get his wife back?

Both the questioner and the girl must repent from zina (fornication/adultery), while being careful not to be lenient in interacting with non-mahram women. If the girl repents before marriage, her parents do not have the right to prevent her marriage on religious grounds, but their obedience is obligatory unless one fears falling into temptation. As for the divorce, it has occurred and cannot be prevented by moral pressure unless there is compelling coercion. The divorced woman must be given her rights. To reconcile with your wife, try to convince your parents, and if they do not agree, obey their command unless you fear temptation from her, in which case it is permissible to take her back. However, not taking her back is preferable out of dutifulness and to avoid problems. In conclusion, whoever is afflicted with a sin must repent and conceal it. Abortion is forbidden unless the death of the fetus is confirmed by doctors' testimony.