DRUNK by D.H. Lawrence from Complete Poems
Has poised on each of its ledges
An erect small girl looking down at me;
White-nightgowned little chits at me I see
And they peep at me over the edges
Of the leaves as though they would leap, should I call
Them down to my arms:
---But, child, you're too small for me; too small
Your little charms!---
The Merriam Webster dictionary defines chit as a pert young woman. The Free Dictionary defines chit as a saucy girl or young woman. And Dictionary.com defines pert as boldly forward in speech or behavior; impertinent; saucy. Therefore, a chit is a boldly forward girl/young woman.
Some nymphets aren't boldly forward. For example, Katya Spivak in Joyce Carol Oates' A Fair Maiden and Belinda in Anne Rice's Belinda weren't particularly aggressive nymphets. However, a number of nymphets are chits like Sue Lyons' character in The Night of the Iguana (1964) and the nymphets in Don't Deliver Us from Evil (1971) [French: Mais ne nous délivrez pas du mal].