Perhaps what confused you is the existence of the noun Cupido (Cupid, Greek Eros), Aphrodite’s mischievous son. But that could not agree with mulier, a woman, and would be nonsensical here.
Catullus actually multiplies Cupid, and even Venus too! Lugete, o Veneres Cupidinesque (3.1).
Incidentally, for anyone curious about qu, which as I said functions as a single consonant like c (cf. the spelling quom for cum), note aqua as the last word of the pentameter, with the initial a remaining short.