Kate Stewart

Kate Lethbridge-Stewart (later just Kate Stewart) was the daughter of Alistair Gordon Lethbridge-Stewart and his first wife, Fiona.

Biography
Kate was five at the time of the Wenley Moor Silurian incident. (PROSE: Doctor Who and the Cave-Monsters)

Kate was the mother of Gordon Lethbridge-Stewart. She ended up estranged from her father, though they re-united circa 1997. (PROSE: Downtime)

By 2020, Kate had dropped the name "Lethbridge" when she became the head of scientific research to UNIT so as to avoid favours. (TV:  The Power of Three)