Mrs. Stone is Paul Stone's mother.
After Paul Stone was admitted to hospital following a lightning strike, his parents and grandmother arrived at the hospital to see him. While Mrs. Stone showed more concern for her son, his father said it would have been better if he had died.
She showed Ted how much Paul idolized him by showing off a painting he had done of both of them and he also had a calendar which showed the days ticked off until every visit to the island.
Even though Granny Stone is her mother-in-law she refers to her as 'Mummy'.