David Merrison's mother

Mrs Merrison was the mother of four children. After her two oldest sons and daughter had been taken by an alien, over three successive Christmases, she and her husband became distant, rarely showing affection for their remaining child, David.

When the next Christmas came, the Seventh Doctor and Ace successfully negotiated the return of the Merrison children, and they became a happy family again. (PROSE: But Once a Year)