。
She'd never socialized in female circles.
Literal
She [topic-は] even-once women [genitive-の] society [in-で] socialized thing didn't-exist.
交際する ('to associate / socialize / mix with') is a Sino-Japanese verb covering social interaction broadly — friendships, professional contacts, and (more commonly in modern usage) romantic dating. The で marks 女の社会 ('women's society / female social circles') as the setting in which this socializing didn't take place, suggesting she grew up or moved in mostly male environments. The phrasing 女の社会 is a somewhat literary, abstract framing — 'the world of women' — rather than the concrete 'with women.' The whole sentence has a vintage, biography-of-a-tomboy flavor.