Green’s Dictionary of Slang

kelsey n.

[presumably a punning ref. to tight as Kelsey’s nuts under Kelsey’s nuts n.]
(US black)

1. a prostitute.

[US] in Amer. Mercury June 230: Kelsy: a broad on a cash basis.
[US]B. Jackson Get Your Ass in the Water (1974) 106: She was three-quarter Kelsey with mossy glossy hair, / she was a stompdown mudkicker and her mug was fair.
[US]Trimble 5000 Adult Sex Words and Phrases.

2. straight hair: a popular hairstyle, favoured by many prostitutes [orig. carnival use].

[US] ‘Pimping Sam’ in D. Wepman et al. Life (1976) 147: She was a stomp-down mud-kicker with kelsey hair.