Frida Kahlo would be pretty recongnisable if you accessorized right...I dunno, I think their hearts are in the right place but if I was gonna go to the trouble of constructing an elaborate costume it'd be because I really liked the character / person I was portraying, not 'cos I wanted to take a stand against slutty nurses.

That, and I'm pretty sure a declaration like "My costume is Mercy Otis Warren, the unsung heroine of the American Revolution!" would be immediately followed by everyone else politely excusing themselves to go get punch.