The offspring or children of an individual were their immediate descendants. (TV: The Dalek Invasion of Earth, The Stolen Earth) They were separable into sons and daughters. (TV: An Unearthly Child et al.)
On Jaconda, a legend told that the Sun God was offended by the queen of the planet, so it sent its offspring, the Gastropods to devastate it in retribution. (TV: The Twin Dilemma)