Just wear what you feel comfortable and confident in.
wear something fun and young and flirty while you can
I see both sides of it. Be comfortable and be you and all that jazz...I hear ya. But another thing you need to be is "ready" if you dress like a skank and a bunch of perv guys try you all the time. Because whether we like it or not, you will find what you look like you are looking for. A girl with booty shorts that say "juicy" or "sexy" on the back is not going to attract a decent guy and will spend most of that day fending off perverts. I know you said it's not about attracting any guy but just thought I would throw that into the hat. If your cool with all that then do your thing. I'm just a dude telling you what I think of when I see these half naked girls in the mall looking like they are at the beach. Think they are trying to get attention and say "hey look what I'm working with everybody". If you are trying to do that or you just don't care either way, then do whatever you like. But if you really and truly didn't care, would you have asked this question and want to know what everybody thinks? Food for thought. Enjoy.
Whatever she feels comfortable in
as I said in past posts
dont dress for a guy, if they trually like you it won't matter what you wear
i say wear whatever you want but if your trying to attract a guy don't wear anything to revealing other wise theyl think your a...you get the picture