Millie Peterson

Millie Peterson was a young girl who was the cousin of Louie Rollins. She aided the Eleventh Doctor on two occasions.

Biography
Millie's mother was Rachael Peterson, and her cousin was Louie Rollins, who was also ten years old and had only been born within a few days of her. (WC: Snowfall)

Millie and Louie had been to a fun Halloween party the night before Louie encountered the Doctor in the warehouse. After the incident, Louie, Millie, and the Doctor were enjoying Bonfire Night when the effigies of Guy Fawkes sprang to life, a result of an alien that had been staking out in the warehouse. The Doctor took Millie and Louie with him on the TARDIS to the warehouse and refuse to take refuge in the TARDIS while he deals with the alien. After he alien and its equipment had been destroyed, the trio returned to Bonfire Night to enjoy toffee apples. (WC: The Night After Hallowe'en)

At Christmas, Millie called the Doctor and invited him to join she, her mother, and Louie to a pantomime of Peter Pan. Though the Doctor was busy at the time, he later remembered the call and arrived at the theatre. The theatre's power was sabotaged by a Brakari, who needed the energy for her and her baby to survive. When Louie lost heat and fell weak, Millie and the Doctor retrieved blankets for him. On the way back, Millie tripped on the icy carpet and almost fell over the balcony, but the Doctor caught her. The baby Brakari attached herself to Millie's back for energy, though the Doctor sonicked it off. She later helped the Doctor reach his TARDIS, which was residing in a deadlock sealed room, by realising that he could use the sonic screwdriver on the screws of the door's hinges. After helping the Doctor carry equipment to help the Brakari and Louie, she joined him, her mother, Louie, and Big Jack on the TARDIS to release the Brakari in space. (WC: Snowfall)

Appearance
Millie was described as being shorter than Louie with curly black hair. (WC: The Night After Hallowe'en)