Green’s Dictionary of Slang

1. a debutante.

1920		F.S. Fitzgerald This Side of Paradise in Bodley Head Scott Fitzgerald III (1960) 204: Both Tom and Amory had outgrown the passion for dancing with mid-Western or New Jersey debbies at the Club-de-Vingt.
1930		E. Glyn Flirt and Flapper 57: Flirt: I thought you said they — halted at a love nest [...] Flapper: They do, unless they fall among us debbies.
1938		Flash! (Wash., D.C.) 21 Feb. 11/1: debbie—Commonly called debutante, and is one who had followed the usual ritual concerning decorum and mannerisms prior to the coming out party and is now definitely in circulation for the desirable company, but her desires usually run toward the older gentry with cash.
1942		‘Marienne’ ‘Solid Meddlin’ in People’s Voice (NY) 7 Mar. 33/1: Dug the bevy of Blue Book Debbies castin’ cool [...] glimmers on Bill Bailey.
1967		New Yorker 20 May 114: We wore white tie and tails every night. We’d hit a few debbie parties and sink back into the Rue.

2. (US) a girl who may frequent surfer circles but never enters the sea.

1985

‘Jennifer Blowdryer’ Modern English 9: debbie (n): Is surfer slang for a dumb beach bunny who never gets wet.