Cassandra Schofield
From Tardis Wiki, the free Doctor Who reference
Cassie Scholefield was the mother of the Seventh Doctor's companion Hex, whose full name was Thomas Hector Scholefield. She met the Sixth Doctor and Evelyn Smythe on two occasions, in 1999 and 2004. (BFA: Project: Twilight, BFA: Project: Lazarus)
Her son, whom she referred to affectionately as "Little Tommy," was only six years old when she was killed by Nimrod in the Forge in November 2004. (BFA: Project: Lazarus)
Hex, who was raised by his father and maternal grandmother, had only one photograph of his mother, which was in his flat in Shoreditch. He regretted not bringing it with him before departing 2021 in the company of the Seventh Doctor and Ace. (BFA: No Man's Land)
