I think, the lady just asked for the shariah rulings regarding the issue under consideration. As her fiance has not openly renounced his faith, there should be no objection towards the marriage.
The Shari’ah (i.e. Islamic Law) does not mention such a marriage, hence there is no prohibition. Since her fiance has not publicly renounced his faith then one cannot say they are forbidden for each other from a legalistic point of view. The objection was not from the Shari’ah, rather it was what I opined to be contrary to it. Since he has privately admitted his renunciation to her I only gave her an opinion regarding the matter based on my understanding. My intentions were not to give the impression that the Shari’ah forbids such a marriage but rather that it is not in consonance with the Shari’ah as I understand it. Nevertheless, I do appreciate you pointing out this potential misunderstanding and I do apologize if my answer gave an incorrect impression to anyone.
I hope I have clarified the issue.
God knows best.