It's nothing the Doctor couldn’t have told her, the Master is thinking. She may not be human, but she wasn't on the Valiant, couldn't have been part of events.

“What I took to that pitiful little backwater was to be a new start for the Time Lord race. I had no fancy-fancy ideals about peace on Earth. They were the means to an end. To be used. Stupid apes. ...Who are you? Apart from being some kind of bacteriophobe.”