Green’s Dictionary of Slang

charlies n.1

also charleys
[? charlie wheeler n. = a woman, and thus her distinguishing characteristics. Ware attributes the term to the predilection of King Charles II (r.1660–85) for décolletage, which would seem fanciful but for the date, which well precedes Aus. use. Partridge (1984) suggests Rom. chara, to touch, to meddle with]

the female breasts.

[UK]Sl. Dict.
[Aus]Sydney Sl. Dict. (2 edn) 2: Dairies - A woman’s breasts, which are also called Charlies.
[UK]Farmer & Henley Sl. & Its Analogues.
[Aus]Stephens & O’Brien Materials for a Dict. of Aus. Sl. [unpub. ms.] 41: CHARLIES: a woman’s breasts: variants – dibs, lemons, dairies, bubs.
[UK]J. Ware Passing Eng. of the Victorian Era 71/1: Charley [...] This same word is used by the general to describe women’s breasts when well developed. It is said this term also comes down from Charles II., and refers to his many mistresses, who certainly displayed their charms as never women did before. Wilder etymologists assume the word to come from Carolian French – ‘cher lis’ – referring to the painted whiteness of the attribute in question.
[NZ]D. Davin For the Rest of Our Lives 345: She pulls the money out from between her Charlies and stuffs it in my hands.
[Aus]N. Lindsay Halfway to Anywhere 177: ‘That barmaid was a top-notcher [...] Five feet nine in her stockings and a pair of charleys a bloke could hardly get both arms round.’ .
[UK]D. Abse In the Cage (1967) 124: Hasn’t she got a lovely pair of charlies on ’er?
[US]D. Greenburg Chewsday (1971) 58: [S]natching a towel [...] and hastily draping his wife’s naked charlies [Simes:DLSS].
[NZ]Tuohy & Murphy Plum Trees 127: ‘The guys in our class..accidentally on purpose bump our charlies. It hurts like anything’ [Simes:DLSS].
[US]J.G. Dunne True Confessions (1979) 40: ‘Not enough you puked on the victim, like you never seen a pair of charlies before’.
[US]H. Rawson Dict. of Invective (1991) 387: Among the others in this collection [F&H]: bubbies, charlies, blubber, butter-boxes, berkeleys, diddies, globes, dugs, and ‘charms’.
[UK]Roger’s Profanisaurus in Viz 87 Dec. n.p.: Charlies n. 70s Tits; breasts.
[UK]Guardian Sport 19 Feb. 12: Charlies on red alert, looking like she’s got a pair of corks stuck up her jumper.