Her parents appear to have separated when she was very young (it was later said that John had deceived Sarah into entering into a bigamous marriage), and Clara went to live with her father on the Isle of Wight. Following John's death in 1818, Balfour was baptized, and taken by her mother to live in London. The two were not well off, and supported themselves by needlework. The mother was highly intellectual, while the daughter was very early in life characterised by a love of reading and of elocutionary exercises.
