"Tell Mom and Dad that it’s the gift you want!"

Ad from Nutsy Squirrel #68 (Nov/Dec 1955)

Interestingly, the “Supergirl” in this ad precedes both the “trial run” Supergirl from 1958 and the debut of Superman’s cousin in 1959 (but not Lois Lane as Superwoman, both in 1943 and 1951).

I should also note that those are some sensible shoes “Superman” is wearing.