What is my Islamic responsibility toward this situation, and should I consult someone else?

The question includes several dilemmas: abandoning prayer and not applying Sharia (definition) (disbelief), committing adultery (a grave sin), the marriage of an adulterous woman while she is pregnant, and the adulterer's request to marry the adulteress after she has married someone else.

Abandoning prayer is considered an act of disbelief (kufr). It is the questioner's duty to advise those who abandon prayer and to shun them if they do not heed the advice. As for adultery, it is an abomination and a grave sin, for which the perpetrator is subject to severe punishment in this world and the hereafter.

The marriage of an adulterous woman who is pregnant from adultery is invalid, and her husband must separate from her immediately. It is permissible to marry her after she gives birth and genuinely repents, and he also repents. The initial adulterer is not permitted to marry her because she is forbidden to believers and because she is married to another man. He must repent to Allah.