Green’s Dictionary of Slang

a term of affection or simply of address between either sex.

1930		J. Lait Put on the Spot 89: ‘Nerves, Babes,’ urged Goldie, passing his smoke to her.
1944		D. Burley Orig. Hbk of Harlem Jive 13: Listen, Babes, you’re mellow, understand?
c.1950		Nunnery versus Fuckery 46: ‘Is that all of it [i.e. the penis] ’ she asked candidly. ‘Sure thing, babes’.
1953		W. Fisher Waiters 174: Babes, you can make me do anythin’ you like.
1957		‘Ed Lacy’ Lead With Your Left (1958) 1: I called out softly, ‘Babes?’ She didn’t answer.
1989		(con. 1950s–60s) in G. Tremlett Little Legs 91: Babes [...] that’s none of your business.
1997		N. Barlay Curvy Lovebox 27: Runnin’ well late. Well fuckin’ late babes.
2000		J.J. Connolly Layer Cake 127: Okay, we won’t be long, babes.
2019		M. Herron Joe Country [ebook] He wondered whether to call her babes.