Green’s Dictionary of Slang

(Aus./N.Z.) a woman who is willing to swap sex for material favours (but not cash).

1982		N. Keesing Lily on the Dustbin 41: Women are distinguished from charity molls if they provide an ‘after dinner mint’ to men who expect, and ask for, this sweet conclusion to an expensive night out. The implication is that ‘minters’ are less promiscuous and more often are ‘going steady’ with their men.
2003		McGill Reed Dict. of N.Z. Sl.