Mary I

Mary I (1516-1558) was Queen of England and Ireland from 1553 until her death. She was the eldest daughter of Henry VIII and the elder half-sister of her successor Elizabeth I.

Biography
Mary once met the Sixth Doctor and Evelyn Smythe when they travelled back to 1554 to fix a time anomaly. On that occasion, the time travellers foiled a plot to assassinate her and place her sister, then imprisoned in the Tower of London, on the throne. At the time, Mary laboured under the misapprehension that she was pregnant by her husband, Philip II. In reality, she was experiencing a phantom pregnancy. She ultimately died childless four years after her encounter with the Doctor. (BFA: The Marian Conspiracy)

She later seemingly became the Doctor's sister-in-law when, towards the end of his tenth incarnation, he was married to Elizabeth I. (DW: The End of Time)