Freddie (The Clockwise Man)

Freddie was a small boy whom Rose met in Sir George Harding's house. He introduced the guests they had while sitting in the gallery. He'd obviously hurt himself, because his mother told him to use his crutch when he walked.

Later that night, Rose came to the conclusion that Freddie was the Tsar of Russia. George Harding wasn't his father, but his second father, the first had been killed.

Lady Anna allowed Freddie to go in the car with the Doctor and Rose, just to see them off to the British Empire Exhibition. He was disappointed, but enjoyed the ride. (NSA: The Clockwise Man)