I think this is unlikely as Tudor queens did indeed have no privacy back then, with information gleamed from laundresses and the like. If she was, she most likely would have said so, even if it wasn't his, because there could be little proof that it wasn't. And even if she might not have wanted to say anything, one thinks there would most likely have been rumours. So it is unlikely. As for the adultery, she was a clever woman, who would most likely have not indulged in that, and it could be wondered whether Henry believed this himself. And as for her being his daughter, I doubt it. There certainly are crazy theories out there. I have never read the Alison Weir book that said this, but I have read many of her books, and I love her work!