Go for it, girl.
Why shouldn't you???
Are there "rules"?
Wear what you like, and if you look good in it, so much the better...
My figure is better now than it was when I was a teenager - frankly, I'd say it's a bit nippy at the moment for short skirts, but if you're going somewhere warm :) , then why not?
I think your dress sounds rather nice. More details please - colour, style etc. Choice of footwear?