What is the religious ruling regarding a 34-year-old divorced daughter who has a son, and who goes out with a man disapproved of by her family, and it has reached the point where she left her mother's home to live with this man, knowing that she left her son in her mother's care? And what is the best course of action for this distressed mother?

Marriage has conditions and pillars without which it is not valid, including the guardian (wali), witnesses, and offer and acceptance (ijab and qabul). The woman's guardian, in order of priority, is: the father, then the paternal grandfather, then the son, then the full brother, then the half-brother (from the father's side), then their sons, then the paternal uncles.

You must not leave the woman with the man without a valid marriage. You should inform her available guardians (such as the grandfather or uncle), according to the order of priority, to prevent her from what is unlawful. If she has no guardian, the matter should be referred to the judiciary.