“It’s a machine that goes… ding! Made it myself. Lights up in the presence of shapeshifting DNA. Also, it can microwave frozen dinners from up to 20 feet and download comics from the future. I never know when to stop.”
The depiction of Elizabeth I is interesting, because it plays on the audience’s expectation. On the surface, she begins the episode as a caricature, a natural prequel to her portrayal in The Shakespeare Code and jokes preceding The Day of the Doctor. But underneath her more jaring characteristics, she truly shines - not only is she perceptive and witty, she is brilliant strategist and leader. To underestimate her is a grave mistake.
The line “I may have the body of a weak and feeble woman” is lifted nearly word for word from a speech given by the historical figure. In it, she continues: “…but I have the heart and stomach of a king, and a king of England too.” [x] Taking up arms and slaying the Zygon, demonstrating quick thinking when she decides to impersonate her own duplicate, providing the Doctor with a potential escape and ultimately figuring out the Zygons’ entire backstory and plan - Elizabeth is certainly shown to fit this description.