I love your Joolme idea (great name, too). Teenage girls are an underserved market (online, at least) and I can see its potential. I have 2 sisters that used to buy costume jewelry all the time. Even as adults, they still do.

The potential problem I see is the social aspect of trying on the jewelry physically and "chatting / giggling / discussing" it. You alluded to some aspect of social design but will it be enough?

P.S. - you might want to do a private registration on your domain names, unless you used a pseudonym or a friend's name :) [edit: since you want to remain anonymous]