Is the engineer, who is not a religious scholar, correct in answering a woman who asked him about the ruling on her taking money from an indebted prisoner to deliver it to its rightful owners, and is his answer to her that her action is correct as long as the money reached those entitled to it considered a correct answer?

What you did is a grave mistake, for it is impermissible to speak about the religion of Allah without knowledge, and this is among the major sins. Even if you were a scholar, it would not be permissible for you to issue a fatwa until you thoroughly understand the question and inquire further from the questioner to clarify matters, for the matter of fatwa is serious and weighty. You must repent and seek forgiveness. If possible, inquire from the woman again, then send the question to a scholar to clarify the religious ruling for her.