Did Venus's a Roman goddess have children?

Yes. The Roman (and thus Greek) gods slept around with mortals and gods... The most famous child of Venus would be Aeneas, the son of prince Anchises and the Venus. Venus (Aphrodite) and Mars (Ares) had four children: Cupido (Eros), Concordia (Harmonia) Deimus and Phobus (Greek only).