A big thanks to Diana Parker for bringing this quote to my attention. As I researched it a bit more, I found that according to Wikipedia, the quote was featured in a 1982 Frank and Ernest comic strip that Bob Thaves wrote about Fred Astaire: "Sure he was great, but don't forget that Ginger Rogers did everything he did, backwards…and in high heels." Does it get any better than that? The official Ginger Rogers website credits Thaves and uses his original line. Often the quote is incorrectly attributed to Faith Whittlesey. Sometimes the quote is attributed to Ann Richards, who popularized the line in her 1988 Democratic National Convention speech, paraphrasing it as: "But if you give us a chance, we can perform. After all, Ginger Rogers did everything that Fred Astaire did. She just did it backwards and in high heels," though Richards credited television journalist Linda Ellerbee for giving her the line. Ellerbee said she heard the line from a fellow passenger on an airplane.
Either way, girl power.