Her name is Jessica (Jess) she is 12 years old.

She was left alone on a planet by the doctor when she was just a baby. She grew up on this planet, not knowing who or what she was. After the doctor died when she was 12, the Tardis teleported to her. She went into the Tardis as it took her to earth, where she was met by Clara, Clara knew what went on, as she was their on the day of Jess's Abandoning. Clara told Jess who she was and who her father was and what had happened. Clara decided to look after Jessica, teaching her how to be 'the doctor'.

This is a fan made Story/Oc set as if peter capaldy never became the doctor.