Penelope Gate

Penelope Gate was the human creator of a time machine, (PROSE: The Room With No Doors) the wife of the Time Lord Ulysses. (PROSE: The Gallifrey Chronicles) In one telling of the Doctor's early life, (PROSE: Celestial Intervention - A Gallifreyan Noir) she was the Doctor's mother. (PROSE: The Infinity Doctors, The Gallifrey Chronicles)

By other accounts, the Doctor's mother was a Time Lord, (COMIC: The Comfort of the Good) or the Doctor didn't have parents at all, (PROSE: Lungbarrow) or was an orphan apparently from another universe. (TV: The Timeless Children)

Biography
Penelope Gate lived in London with her husband. She felt trapped and suffocated by her domestic life, prompting her to look for some way to escape it altogether; she wished for a divorce, although she did not seem to hate her husband as such. The two had a son, but he died when he was a year old.

The first time she successfully used her time machine, around three years after her son's death, she used a lightning strike to charge it up. She travelled to 1996 where she obtained a mutated Tzun battery to power her machine. There she met Joel Mintz, who became her companion, although they became stuck in 16th century Japan. There Penelope met the Seventh Doctor, who took her back to her own time of 1883. (PROSE: The Room With No Doors)

Later in her life she met the Time Lord Ulysses, whom she married. Unbeknownst to the High Council, they had a son together (PROSE: The Gallifrey Chronicles) on the Otherstide holiday. (PROSE: Celestial Intervention - A Gallifreyan Noir) The Infinity Doctor remembered that his mother's name was Penelope. (PROSE: The Infinity Doctors) Penelope and Ulysses became friends with Mr Saldaamir, with whom they frequently went exploring. The trio also associated themselves with Lady Larna, who was from their future. (PROSE: The Gallifrey Chronicles)

When the Time Lord Marnal threatened to expose Penelope's and Ulysses's activities, they used the telepathic circuits of his TARDIS to wipe his memory, and they dumped him on Earth in England, 1883, to board with Penelope's mother. (PROSE: The Gallifrey Chronicles)

Legacy
Maris found documentation of the Doctor being born to "a human mother and a Time Lord father", but also found four other accounts of the Doctor's birth. All five accounts disagreed with each other. (PROSE: Celestial Intervention - A Gallifreyan Noir) Among other of the Doctor's secrets, Lady Peinforte learned of the Doctor being half-human on his mother's side on the TARDIS Wiki, though she claimed it was "much disregarded". (PROSE: Lady Peinforte)

Appearance
Penelope was short (PROSE: The Room With No Doors) and slightly plump, (PROSE: Unnatural History, The Infinity Doctors) with long red hair. (PROSE: The Room With No Doors, Unnatural History, The Infinity Doctors, The Gallifrey Chronicles, A Big Hand for the Doctor) She wore round spectacles. (PROSE: The Room With No Doors)

During her adventures with Joel Mintz, she wore "what looked like a Victorian safari outfit", and her hands were gloved. (PROSE: The Room With No Doors) At the Shoal, she wore an ankle-length skirt and prim white blouse, with her hair "[hanging] wild to her waist". (PROSE: The Gallifrey Chronicles) She wore an elaborate gown in a framed print in Daniel Joyce's office. (PROSE: Unnatural History) The Doctor kept a portrait of her and her husband hanging above his fireplace. (PROSE: The Infinity Doctors)

Behind the scenes

 * Kate Orman, creator of Penelope Gate, said it was "absolutely clear" in her mind that Daniel Joyce abandoned Penelope to raise their son on Earth. This was meant to explain why, in Black Orchid, the Fifth Doctor said he always wanted to drive a steam train when he was a boy.
 * Orman's short story All Mimsy Were the Borogoves introduces the Joyce-Gate hypothesis, which suggested that the Mim were actually slime molds possessed by intelligences from higher dimensions, in a reference to her characters Daniel Joyce and Penelope Gate.