Hot damn. Finally a girl Robin costume I support.
http://www.80stees.com/products/Ladies-Sexy-Robin-Costume.asp It's still not canon of course but...I don't CARE, it's close enough. Especially if you replaced that dinky cape with a long black one, I could cut the hood off my death robe and be all set, use my own utility belt if I wanted to be more functional. Now I wish I'd bought tabi in Japan, but they really didn't have my size. Man I want that dress, even though I won't look nearly as good as that girl. I'd wear it all the time. Come on, leave the gloves and mask at home and you can totally wear that to the mall...
I would wear a size Small by the way. Just, ya know. Just sayin.
A store y'all might not know carries superhero tees -
http://www.topshop.com/webapp/wcs/stores/servlet/CategoryDisplay?catalogId=19551&storeId=12556&categoryId=42325&langId=-1&top=Y They have some fairly snazzy girl comic tees that I've never seen anywhere else. Gotta love that Batgirl made the main image.