Emily
From Tardis Wiki, the free Doctor Who reference
Emily was the second adoptive daughter of Sarah Jane Smith. She gained Sky and Luke, as brother and sister.
Birth
The Doctor and Peri called Sarah Jane, Clyde Langer, Luke Smith, Sky Smith and Rani Chandra to attend their wedding, on Gallifrey. But the wedding not happened in the right date, May 9, 1987. Peri wass pregant of twins. One, a girl, she gived to Sarah Jane, calling the baby Emily.