Granny Five

From Tardis Wiki, the free Doctor Who reference

Granny Five was one of the Doctor's seven grandmothers and, according to the Thirteenth Doctor, her favourite.

She told the young Doctor about the Solitract as a bedtime story, and claimed that Granny Two was a secret agent for the Zygons. (TV: It Takes You Away)

By the time after the Last Great Time War, the Ninth Doctor believed that his entire family, (TV: Father's Day, The Empty Child) and therefore Granny Five, (TV: It Takes You Away) had died. (TV: Father's Day, The Empty Child) Similarly, the Thirteenth Doctor believed her whole family was dead. (TV: The Woman Who Fell to Earth)