Sandra Mitchell

The mother of Adam Mitchell was an old woman. When Adam went to travel in the TARDIS, she believed he was still working at Henry van Statten's museum. Later, when Adam had an implant in his head from 200,000 (which, when you click your fingers, a small circle opens on his head and your brain is visible) he tried to record Internet codes on her phone when she was out. When Adam tried to upload the Internet, and The Editor read his memory to find out The Doctor's weakness's, he abandoned Adam back at his house in 2012. Adam's mum returned, saying time flys "just like that" and clicking her fingers, then watching in horror as her son's head opened up.

Behind the Scenes
In the episode, her credit-name was Adam's Mum, an official source, however names her Sandra. (REF: Doctor Who: The Encyclopedia)