Jeanne-Antoinette Poisson

Jeanne-Antoinette Poisson (1721–1764), often known as Reinette or Madame de Pompadour, was a member of the French court and the official chief mistress of King Louis XV of France.

Biography
The Tenth Doctor met and romanced Reinette several times in her life as a result of time manipulation by the Clockwork Droids. She called the Doctor "my lonely angel". Using his Time Lord abilities, he examined Reinette's mind to look at her past experiences. It was not long before the Doctor realised that Reinette was also using this opportunity to gaze within the Doctor's mind at his lonely childhood. When he asked Reinette how she managed that, she said that "a door once opened may be stepped through in either direction."

When the Doctor was stranded in the 18th century, she showed him a way back to his original time. The Doctor invited her to travel with him but, due to the time differential, she died before she could do so.

In the 51st century, the starship SS Madame de Pompadour was named for her. Reinette herself would briefly set foot upon the vessel when she stepped through one of the time windows that had been created on the vessel. (TV: The Girl in the Fireplace)

Letter to the Doctor
"My dear Doctor: the path has never seemed more slow, and yet I fear I am nearing its end. Reason tells me that you and I are unlikely to meet again, but I think I shall not listen to reason. I have seen the world inside your head and know that all things are possible. Hurry though, my love: my days grow shorter now, and I am so very weak. Godspeed, my lonely angel."

- Jeanne-Antoinette Poisson

Personality
Reinette showed incredible intelligence, accepting the futuristic world well and the fact about the Doctor being a non-human.

Reinette showed amazing courage. Instead of running away, she defied the Clockwork Droids and stood up to them, even at blade-point.... pointing out how the Doctor will come.

Reinette also showed great compassion, pitying the Doctor for his loneliness despite how he isn't human.