The Woman (The End of Time)

The Woman was first seen in a church on December 23 2010. She told Wilfred Mott of the church's past: it was once a convent that had been attacked by a demon from the skies in the 1300s, and was saved by a "saintly physician". After saying that the physician may be needed again, she vanished.

She next appeared to Wilf on Christmas Day, her image appearing on television, which only Wilf could see. She told Wilf that he needed to take up arms, and that the Doctor's life could still be saved. Before vanishing again, she warned Wilf not to tell the Doctor of anything she had said to him.

She once more appeared to Wilf on the Vinvocci's spaceship, telling him that it was the Doctor's final battle. He asked her who she was, but she remained silent and told him that she was lost long ago, before disappearing once more.

She was revealed be a mysterious Time Lady, and could be seen in a weeping position standing by The Narrator, who was revealed to be Rassilon. When the Doctor looked at her, she briefly uncovered her face and looked at him and shed a single tear; before she covered her face again, the Doctor looked on at her in shock, indicating that she was someone from his past whom he loved. When asked by Wilfred who she was, he replied with only silence. (DW: The End of Time)

Behind the Scenes
During filming, newspapers The Daily Mail and The Daily Telegraph announced that Claire Bloom would be portraying the Doctor's mother. However, the character was never explicitly identified as such during the special, but the Doctor does react strongly to seeing her character, leaving it a mystery.