Horrified by her Father's abuse of her--was it the Cruciatus? That sort of thing is just awful, and I have a sneaking suspicion that he got away with it too, even though Auror Scrimgeour showed up to investigate. Ugh.
Molly's fiery contrariness is lovely to behold. I am tickled at her decision to punch her cousin rather than hex her (though violence isn't a good answer, of course, but choosing an ultimately less harmful outlet should be commended, perhaps?), and her spine in standing up to parents who are trying to marry her off.
And her brothers! Oh, goodness, Fred and George are their reincarnations, aren't they?
And of course Arthur wanted to be a pirate, too! Let's hope that they find their lives together to be a satisfying adventure.