that's cool...
My daughter is almost 6 and has had a small acoustic guitar and a 5 piece drumset since she was 3. She's really into music and pretty much listens to anything- I play all kinds of crazy stuff while she's in the car. She doesn't like Iron Maiden though, she's scared "of that ghoul singing". She'll run around the house strumming her guitar and singing her head off, and sometimes she'll ask if we can go in the basement and have a jam session- she plays her drums and sings at the top of her lungs and I play guitar at my workbench. She even arranges "songs"- she'll tell me when to play and when not to play. I never pressure her about lessons, i just let her enjoy the instruments when she feels like it.
I feel that she's finally old enough to come to one of our shows (with the help of a friend of course) because i've explained that there's a lot of people and it's really loud and she seems ok with it. She's been to a couple of outdoor concerts and really liked it. I have some industrial ear muffs she can wear, and as long as she stays with my friend in the back she'll be out of the way of the kids doing their thing. I am just waiting until we play somewhere that's not a messy disgusting crap hole with lots of drunk a-holes, or the potential for fights. I'm thinking if she sees me play on stage she might be inspired to play more.