Im 33 and just started playing the sax in the last few weeks, funny you should ask because I was just reading through the mails and thinking how young everyone was.
Your very lucky to be so involved in music so young - I dont believe your age matters, just have fun, be confident and imagine how good you'll be at my age !
Wish I'd started younger, I was far to worried about what I was missing while I was practising, not realising the fun bit is the practicing!
It really makes me smile after a rotten day at work, It makes my neighbours laugh, my girfriend sing along, and now when I go in the pub across the road, they all sing Merrily to me as I come in and when I leave. Its very funny!
Good luck and keep playing - Im hoping for Grade 1 in November!