What's the problem? The whole series is about acceptance really and she's never mentioned this before because there was no need to, it was irrelevant to the story.
She was asked whether he's ever found true love and answered the question, it's not as though it's something she made up on the spot as she has pages and pages of back-story and character development already written.
It doesn't change the story in any way does it? Or are people so shallow that this changes their perception of the character to make him unacceptable.
It won't affect kids reading the books at all, the books don't mention it, so why should anyone really be bothered?