So I may be a bit of a geek, but I'm LOVING the new design of Batgirl done by Babs Tarr. The new Batgirl came out a while ago but you can always get a second print edition or a digital version. Definitely worth a read, Barbara is now younger and sassier: ingredients for Awesomeness. So this is my rendition of what I think would be normal street-wear for Barbara Gordon - also I think this post just sums up my recent TV watching (Constantine and Gotham). - If you haven't watched those already, I highly suggest it.
So normally I don't wear dresses or skirts that that hit right at the knee, due to my height, but I feel the turtleneck asset really added to my length. I'm also a firm believer that you can wear whatever you like, as long as you feel bad ass in it... or like Batgirl in it.
Hat: Aldo Accessories
Boots: Dr. Marten (old but similar here)
Necklace: Victoria Secret (old but similar here)
Sunglasses: Nine West (from TJMaxx but similar here)
Faux Leather Jacket (last seen here): Amazon