My oldest daughter will sit at the piano and play some truely great classical pieces (she's getting pretty good at the sight reading thing)... then, she goes in her room, down tunes the guitar and proceeds to play the darkest riffs.
Personally, I think her classical piano training is paying off, making her a better metal player, but that's just a personal opinion.
Sometimes, we sit together and crank our amps, and play riffs from March Slav... Downtunes, with distortion, and annoy my wife - another music snob who hates metal. Heh heh.
You and your daughter jam metal together?
I hope I someday have a daugter that cool and talented LOL!