The situation in which she said it was somewhere in between, I think. It was in response to a question about whether Dumbledore ever found "true love". Perhaps, as far as she was concerned, the evidence was there in the text, for those with eyes to see.

In this particular case it's not just about whether (or how far) she went beyond textual evidence, but also about what her audience was prepared to hear. For example, there's no evidence in the book that Dumbledore is straight, but had she answered that he just never found the right girl it's highly unlikely that her remark would have been subject to the same kind of interrogation.