
Earlier use in Frank and Ernest (c. 1982), by Bob Thaves, as the characters observe a billboard for a "Fred Astaire Film Festival: "Sure he was great, but don't forget that Ginger Rogers did everything that he did… backwards and in high heels."
Quoted in
Misattributed
Context: If you give us the chance, we can perform. After all, Ginger Rogers did everything that Fred Astaire did. She just did it backwards and in high heels** Keynote address, 1988 Democratic National Convention