stewer, n. — Green’s Dictionary of Slang

stewer n.

[her stewing up of gossip, rumours, slander etc. or play on old hen under old adj./SE old hen, which would be stewed]

(US black) a woman of 45 years or more.

1941		D. Burley N.Y. Amsterdam Star-News 8 Mar. 13: When you hear the boys talking about ‘fine fryers, mellow broilers, fine young hens, roasters, and stewers’ they’re [...] describing the womenfolk [...] a stewer is 47 to 60.
1944		D. Burley Orig. Hbk of Harlem Jive 66: All that’s in the House Without Chairs [...] are a bunch of Gal Officers, Harpies, Stewers and Chicks That Play It Hard. [Ibid.] 88: The Jiver expresses his condemnation of the female of 45 and up [...] by designating her as a ‘stewer’ or in some cases just plain ‘harpy’.