Ah apologies, I missed the thrust of your question but surely the doll's name is just a play on words meant to evoke the nickname "Suzie Q," which was fairly po

Ah apologies, I missed the thrust of your question but surely the doll's name is just a play on words meant to evoke the nickname "Suzie Q," which was fairly popular once upon a time, back when people commonly named their little girls Susan. As to which came first, the nickname or the dance step, I doubt there's any ironclad attestation for that (although I did find an old book from 1901 where someone had named their cow Susie Q), but anyway since trendy dance steps are most often named after something else, and not just given monikers ex nihilo, my guess is the nickname came first.