You are probably even a bit smaller than me. I buy the largest child size and I find these fit pretty good. I have a girl's size 14 North Face down jacket. Boy's size 14 or 16 Columbia shirts fit me well. The Patagonia girls size 14 zip-top underware fits too. The best fitting jacket I have is a ArcTerex x-small men's jacket. I have a friend who is taller but very skiny and she has really good luck with men's x-small sizes. Sleeves are often too short in girl's sizes, but boys sizes seem to have longer arms. Another thing I like about kids clothes (mostly REI) is that to keep them cheaper, they are very basic - no bells and whistles - and I really like that.

But anyway, thanks for the evaluation of the jacket. I will remind myself not to get one.