Douglas Harper's Etymology Dictionary
also nymphet, nymphete, "sexually attractive young girl," 1955, introduced by Vladimir Nabokov (1899-1977) in his novel "Lolita" to describe alluring (in the eyes of some men) girls age 9 to 14; from nymph + diminutive suffix. Used from 17c. in sense "a little nymph."
n. (alternative form of nymphet English)
Usage examples of "nymphette".
She makes Leila Carlea, the divine nymphette, look like a gods-forgotten lump.
In his dreams these charming nymphettes were climbing a ladder on their way to bed, and he was on duty beside the ladder watching them climb, catching glimpses of their slightly soiled knickers as they disappeared into the sky.