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)