Thrift Store Find: Mad Engine Marvel T-Shirt

Several weeks have passed by since finding anything of real importance at the local thrift stores but that changed yesterday. Friday the 13th was lucky for me for I found a XXL Marvel t-shirt made by Mad Engine for three dollars. This one features Captain America, Storm, Spider-Man, Wolverine, Iron Man and Hulk. There is also a woman at the top that I think is Janet van Dyne aka the Wasp as Giant Girl but I'm not for sure since I have never seen that costume before. The following picture is from a seller on eBay who writes that the mysterious woman is Electra (you can view his small t-shirt here):

Anybody know who the mysterious woman is? My google-fu is failing me at the moment.