Yes, I understand that sort of trouble completely. It's kind of like coming up with a name, really, but I figure the only thing you can really do is nail down what you want before hand and then start writing. Good choice to just keep it simple rather than ramble on vaguely like I do when I haven't fully decided on an appearance.
I'm all like 'So her hair is wavy...but not too wavy and sorta does this and that, and she's tall but not like SUPER tall and blah blah blah' =P

I'm not an expert on fashion either, but I'm kinda sorta in to designing, maybe we could work something out together? What did you have in mind overall? Was there something you were trying to evoke with her style? And yes, go ahead and post that reference picture. You mean for her clothing, right? Not an actual appearance picture? I'd definitely prefer it if we can get it into words though, I like to keep stuff pretty purely writing focused.

Oh yes, if they were just joking about the dangers of Iona's talent then that is totally fine, I didn't get an overtly negative vibe from the fast flyer's tone and was only really pointing it out in case you intended to make the dangers of storms and people mistrusting her talent be a defining character trait. You can go ahead and edit it though, if you like, but regardless, storm talents would still be a very volatile talent I believe so I think it fits.