nymphette (n.)

also nymphet, nymphete, "sexually attractive young girl," 1955, introduced by Vladimir Nabokov (1899-1977) in his novel "Lolita" to describe an alluring (in the minds of some men) girl age 9 to 14; from nymph + diminutive suffix. Nymphet was used from 17c. in sense "a little nymph," but this was poetic only by late 19c.