Green’s Dictionary of Slang

a girl aged 10–14, also an adolescent boy.

[1947		Tuscaloosa (AL) News 13 Mar. 7: Fourteen-year-old [...] A [...] is a serious bubble-gummer, ambitious to blow the biggest and best bubbles in town].
1967		W. Murray Sweet Ride 130: The kids were strictly bubblegummers, spoiled little punks.
1975		J. Wambaugh Choirboys (1976) 67: A high speed chase after some joyriding bubblegummer. [Ibid.] 247: Bad enough working with adults without taking crap from bubblegummers.
1981		J. Wambaugh Glitter Dome (1982) 118: Then two bluesuits had to go and bring in a bubblegummer.
1993		Tarantino & Avery Pulp Fiction [film script] 58: I don’t go joy-poppin’ with bubble-gummers.
2023		(con. 1962) J. Ellroy Enchanters 367: An ageing bubblegummer with a pricey Mont Blanc pen.