Green’s Dictionary of Slang

1. (UK Und.) a euph. for a prostitute.

1667		Dryden Sir Martin Mar-All Act IV: Ile undertake I n’ere enjoy’d her Neice under the rate of 500 l. a time; never was womans flesh held up so high.
1674		T. Duffet Mock-Tempest III i: If five or six Gallants stood in the way, Lord what rustling and cringing was there to Madam Stephania?–Aunt, cries one, how does my little Neece?
1696		J. Dunton Night-Walker Dec. 14: I have followed the Trade of being an Aunt, says she, ever since I was not able to be any longer a Niece.

2. (US) in sadomasochistic use, a dominant female.

a.1989

Corporal 10 in Murray & Murrell Lang. Sadomasochism (1989) 97: Stimulating correspondence sought with long-lost strict aunt, or spoiled, sassy niece.