Matilda (Lost in Time)

Matilda was a lady-in-waiting to Lady Jane Grey during her nine day reign from 10 to 19 July 1553.

Biography
Matilda plotted to kill Jane so that, rather than being executed quietly like an average traitor, she would die a martyr. However, her plan was foiled by Rani Chandra, who had seen her with a messenger. She woke Lady Jane with her shouts. (TV: Lost in Time)