Green’s Dictionary of Slang

(Aus.) a woman.

1839		H. Brandon in Miles Poverty, Mendicity and Crime; Report 165/1: Shalers, girls (country phrase).
1848		G.W.M. Reynolds Mysteries of London III 71/1: Cop that young shaler unto thee.
1859		Matsell Vocabulum 78: shalers Girls.
1864, 1867, 1870		Hotten Sl. Dict.
1881		Newcastle Courant 2 Dec. 6/6: He’ll not trouble us tonight, nor will the shalers [...] Chloroform has done the trick for them all.
1895		C. Crowe Aus. Sl. Dict. 72: Shaler, a girl.