Billis

Billis was one of the harvest rangers on a snowy planet in 5345.

She was present when Madge Arwell was caught in the forest and identified her as a time traveller. When Droxil tried to interrogate her, Madge pretended to cry. She thought it was questionable to shoot or interrogate her, so Droxil agreed to put down his weapon.

All three were caught off guard when Madge aimed her revolver at them. She took them prisoner, handcuffing Droxil and Ven-Garr to poles inside their Androzani harvester but allowing Billis to help her with the scanner. Madge tried to get Billis to steer the Harvester to where her children were, but she didn't know how to drive it. The three rangers were teleported to safety, leaving Madge onboard the Harvester. (TV: The Doctor, the Widow and the Wardrobe)