Green’s Dictionary of Slang

1. (US teen) attractive, sexually alluring.

1885		‘High School Sl.’ in N.Y. Dispatch 31 May 7: He was regular peaches.
1911		Irving Berlin ‘Alexander’s Ragtime Band’ 🎵 Come on and listen, / Sure! / To a classical band what’s peaches.
1926		Odum & Johnson Negro Workaday Songs 214: Anna yo’ peaches, but I’s yo man.
1981		(con. 1940s) O’Day & Eells High Times Hard Times 96: I’m not your ordinary peaches-and-cream band chick [...] I don’t come on as a pretty girl in ruffles who flirts.

2. (US) fine, excellent.

1916		G. Squiers Skitologues 11: The man who wrote the music of ‘Ev’rything is Peaches down in Georgia’.
1919		H.C. Witwer Smile A Minute 52: Everything has been peaches.
1935		C. Odets Awake and Sing! Act III: Everything is peaches and cream.
1947		C. Willingham End as a Man (1952) 158: He’s the sort of good fellow you can get along with if he’s physically afraid of you. Then he’s peaches.
1960		C. Cooper Jr Syndicate (1998) 85: Everything’ll be just peaches.