She's smokin.

The people who say that seem to miss the point of the original Toadette name. Toad + ette, in which ette is to make the noun feminine. The real question would be why Toadette would be called Peachette with the Super Crown, but in that case it could be another play on the alternate usage of "ette" being diminutive or smaller. A smaller Peach… Peachette.

The naming scheme works to explain it all away, unless I'm missing something.