Ah ok. that's a good start. I see three good strengths there. speed, stamina, and possibly ice resistance 25% If you wanted it? Based off her being able to handle the cold. If so a 25% weakness to fire is also possible, with the not handling hot weather so much, thats a good weakness. You'd just need two more, (strength maybe?) then its just the fighting style to work out. If you go that way, ice and cold might be a good choice of element for her, but thats up to yourself. XD you can have two elements and mix in other powers as you see fit.
Low defense, maybe she has slower reflexes and doesn't react to danger as fast as others? that would also qualify as a weakness. Seeing as she has no real formal fighting style (which is fine) you could just go into some detail on how she fights. She probably moves allot and possibly tries to pepper her foes with blows? I'll let you ponder that.
Stealthy Jun edit: Also, don't worry about your starting tier. Based on those notes, you'll easily get a 2-5 minimum, which is where we try to get people's apps worth at.