Salchow : Double Salchow as Waltz jump : ??

This morning, one of the little girls at the rink asked me,
"are the salchow and double sal the same, like this?"
She proceeded to do the 3-turn entry to the salchow.

I was caught off-guard. "Huh?" I said.

She repeated, "are the salchow and double sal the same, but double sal has one more rotation?"

"Oh yes, of course!" I replied, "If the double sal wasn't the same, it would have been called a double-something-else"

After a moment's hesitation, she asked,
"Then why isn't the Axel called the triple Waltz jump?"

"Uh, I don't know!!"
Normally I would have a clever response, this time I just wasn't on top of it. Blame it on jet lag!