They are exactly right. It doesn't often happen to us, except sometimes with the males thinking they can better us. Females who haven't kidded can often become that bit more aggressive though if they want to be top of the heap. When she does it, coup her over, and sit on her. Best way to coup is stand on one side of her and pull the front leg furthest away from you in towards you. This will put her off balance, and your hand on her shoulder will tip her over. As soon as she's down, kneel or sit on her so that she can't get back up until you let her. I've never done that with a female, but I have with males- especially when they're between a year and 18 months old as thats when they're most uppety.
Beth