M.L.
here is a great superhero party, maybe it will have some ideas to help ,lots of kids love this theme, we'll be doing it for our boys soon too:
for the capes, if you don't sew, just cut a yard of fleece. easy!
http://www.ambrosiagirl.com/blog/dax-and-kais-superhero-p...
lots of lady superheros, super girl, wonder woman, rogue, she-ra, cheetara (from thundercats), bat woman,
http://www.infobarrel.com/Twenty_One_Sexiest_Female_Super...