Freda Gore

Freda Gore (née Wardlaw) was the wife of James Gore, the mother of Mary Gore and Isobel Gore, and grandmother of Gordon, James and Alistair Gordon Lethbridge-Stewart, and Lizzie Davies. (PROSE: The Forgotten Son)

The Brigadier told the Fifth Doctor that one of his grandmothers died in 1955. (PROSE: The King of Terror)