Am i too young for this bag?

I don't think so at all! In fact, when I bought a pink tonal bag as a summer bag I worried that it was too "cute" for me because I'm soooooooo over the hill at 22!
 
I think it's great. Coach has really started to become more of a younger generation things nowadays (gosh, I sound so old here.. I'm only 25!) The higher-end, more expensive Coach bags are definitely geared more towards adult, but their funky patchwork and bright colored bags definitely seem more for late teenager-early 20s. My sister is a senior in HS and has quite a few Coach bags, as do her friends. It's a more affordable form of a "designer" bag and I think it's a good way to go for teens!

Now over in the Louboutin forum there is a discussion on whether CL heels are appropriate for a 15 year old.. and to that my answer is NO NO NO NO!!!!

But with Coach you are absolutely fine. :P