Erisa Magambo

Captain Erisa Magambo was a female officer working with UNIT in the early 21st century.

During Easter 2010 she and UNIT where called out on site after the Number 200 bus had vanished into a wormhole. She along with Malcolm Taylor managed to get in contact with The Doctor. When the Doctor warned UNIT that an Alien swarm was coming to Earth, she held Malcolm at gunpoint and asked him to close the Wormhole, but in turn that might have meant that the Doctor and the Humans would have been trapped.

In the end the Doctor managed to get the bus to safety and Malcolm closed the wormhole. She later thanked the Doctor and gave him his Tardis back after UNIT had found it in Buckingham Palace Garden. (DW: Planet of the Dead)

Parallel Worlds
She was part of the operation to remove the insectoid entity on Donna Noble's back. She was in charge of a special division of UNIT, most likely the sole surviving British division in the alternate timeline. She with the help of Rose Tyler, sent Donna back to prevent the events which would result in the Doctor's death and eventual world-wide disaster. (DW: Turn Left)