Nova Osgood was the sister of Petronella and daughter of Frank Osgood.
Osgood was jealous of Nova, who got away with anything (PROSE: For the Girl Who Has Everything) and was, she believed, prettier than her. (TV: The Day of the Doctor) Nova always left her Christmas shopping until the last minute and, in 2011, simply put her name on Osgood's present for their father. (PROSE: For the Girl Who Has Everything)
In 2013, a Zygon that copied Osgood's appearance mocked her, saying that she should have copied her prettier sister. (TV: The Day of the Doctor)