Abby was a young girl who briefly travelled with the Eleventh Doctor.
Early on Christmas morning, Abby and her brother, Danny, sneaked downstairs to see what presents they got. The Eleventh Doctor arrived, warning them not to open one of the boxes. The activation signal reached the Zentrabot inside the present, who broke out of the packaging and attacked. The Zentrabots kidnapped thousands of children across Earth, including Abby, taking them into a holding cell on board the Zentra mothership.
Promising Abby and Danny's parents they'd be only away for five minutes, he took them away for another trip. Queen Shemura's image invaded the TARDIS' telepathic circuits. The signal was traced to a palace on the planet Philastra. After seeing Shemura project a fabricated invasion that had wiped out most of her people, the Doctor agreed to her plea to release her from suspended animation. When released, she revealed that she turned on her treacherous subjects and killed them.
Shemura took the TARDIS key and threw the Doctor, Danny and Abby in prison. With the help of the prisoner Alaban, the three escaped. Before Shemura could enter the TARDIS, the Doctor convinced her that only he could pilot it. The Doctor boosted the telepathic circuits, bringing the mental projections of the dead through. The mind control on Shemura's guards was blocked, and the Doctor locked Shemura back into stasis. The Doctor then realised Danny and Abby's parents might be wondering where they were. (COMIC: The Tomb of Shemura)