What the hell is Harry Potter trying to suggest???

OK I've known for a while that Anne Boleyn's portrait was in the halls of Hogwarts, I'd never seen it so i thought that it was just a load of bull put on wikipeadia... again. But today as i was working hard in class, surfing google images.. and i seen the puppy headed Hermione Granger looking in the direction of the beloved Queen Anne. I realised as many of the other wonderful women on Anne Boleyn websites that these Harry Potter people are trying to say that Anne was a witch!! What the Hell?!?! If you're going to believe that then you may as well believe that she had a 6th finger and a third breast!! This really pisses me off. The Harry Potter Wiki says that she was not a witch but a squib (a squib being a non-magical person born into a magical family) REALLY?!?! What the hell yeah I'm sure Mary, George, Elizabeth and Thomas were witches and Anne was the exception. I know Harry Potter is a load of plagiarised crap, but I'm still not fucking happy with it.