Aphasia
From Tardis Wiki, the free Doctor Who reference
Daughter/Sister of Mine was a part of a criminal family known as the Family of Blood. She appeared to be the youngest memeber, because she possessed the body of Lucy Cartwright, a little girl. When she was caught by the Doctor after her family tried to take his life essenece, he trapped her inside every mirror in existance, visiting her once a year, every year. In the book Martha In The Mirror the doctor mentions "A Girl With A Red Balloon" , Possibly meaning that she was haunting the castle by being in the mirrors
