Major problem I have with this theory is that Molly is anything but frigid and let us face it, she makes um "things" grow. I say she's isn't Mab. She's Titania, it's why we have never seen her, and right now she is righteously pissed at Mab for boinking Harry. Which is why Mab broadcasted it, "hey biotch, look who I'm bumping uglies with! nanny nanny boo boo!"