Board Thread:The Last Sovereign Discussion/@comment-27713488-20181103233945/@comment-36170150-20190405150611

Robin was only adopted years after Wendis died.

I think you might be reading a bit too much into it, Wendis was observing Simon the best she could from the depths of the tower ever since we entered the tower to build the extradimensional HQ, so she had some faint ideas of who Simon's companions were, which is why she knew she could kidnap the succubi to draw Simon deeper into the tower. She probably noticed Simon and Robin had a father-daughter relationship and was going to mention it, but it wasn't worth having that conversation then since there were more pressing issues.