foundress.

From Middle English founderess, founderesse, foundress (“female founder or builder of a city; female founder or benefactor of a religious house; (figuratively) female inventor or originator; (figuratively) a source”) [and other forms]; from founder, foundere, foundour (“founder or builder of a building, city, country, etc.; builder or endower of a church, college, monastery, etc.; benefactor or patron of such an institution; charter member of a guild; first head of a religious organization; inventor, originator; (figuratively) earliest of a class of people; (figuratively) a source”) + -esse (“suffix forming female forms of words”). Foundour is derived from Anglo-Norman fundur, Old French fondeor, fondeur (“creator, instigator, founder”) (modern French fondeur), from Latin fundātor (“founder”) (rare), from fundō (“to make by smelting, found”) (ultimately from Proto-Indo-European *ǵʰewd- (“to pour”)) + -tor (suffix forming masculine agent nouns). The English word is analysable as founder + -ess (suffix forming female forms of words).

From founder (“one who founds or casts metals”) + -ess (suffix forming female forms of words). Founder is derived from Middle French fondeur (“owner of a foundry; ironworker in charge of smelting, founder”) (modern French fondeur), from Latin fundātor (“founder”) (rare): see further at etymology 1.