I think that's great to encourage your daughter to chase her dream. I have four kids, ranging from 14 down to 1 (next week), and they all seem to have an interest in music in some form. My 7-year-old daughter has a passion for ballet, and my 12-year-old son actually has my old e-drum kit. They both have electric guitars, as well, and my 14-year-old daughter got a violin for her birthday last year.
Even with the accessibility that they have to instruments, they come and go from it so quickly. I know that they may pick it up an put it down many times over the course of their childhoods. My wife and I homeschool them, so we actually offer incentives for them to at least learn about the instruments. All three of them love to come to band rehearsals with me, and any gigs that we play that are family-friendly. My older two have even learned parts of the set-up and tear-down processes at shows.
Then, there's the baby. He's already watching me very intently when I practice at home. He loves to sit at the kit and play around. It may be too early to tell, but I have a good feeling he will follow his older siblings.
After all this, my point is that it's great to encourage children at any age. I didn't play an instrument until I was in my early 20's. I sat down behind a drum kit in '99, and that was all it took. And I get words of encouragement from my parents, even now, and I think it is one of the best forms of encouragement. I have an amazing amount of support in my life, all around me, for what I do, but it just adds to it when you get a feeling of making your parents proud, no matter how old you get.
--Shawn.