Lucy Cartwright's father
From Tardis Wiki, the free Doctor Who reference
Joan Redfern suggested that Lucy Cartwright's father and mother realised that Daughter of Mine was not their child and were swiftly killed. (TV: The Family of Blood)
Behind the scenes
Doctor Who: The Encyclopedia confirmed Redfern's beliefs about the Cartwrights' deaths as true; after being possessed, she went home and killed Mr and Mrs Cartwright.
