Upon meeting the Eleventh Doctor in a park, neither of them knowing the other's identity, a young Clara listed her gran among the things she was "always losing". (WC: The Bells of Saint John: A Prequel) In her youth, Clara was told by her gran that sunlight was a good way to repel germs. (TV: Kill the Moon)
When Clara, now an adult, attempted to make a family Christmas dinner, her gran attended, along with Dave and Linda. Despite her old age, Clara's gran perked up upon seeing the Eleventh Doctor naked, and was very interested in taking him up on his suggestion to play Twister. She was disappointed with the more serious Christmas crackers that Linda had brought, preferring ones with jokes. The Doctor later expressed a similar opinion.
She had been married, but her husband had apparently passed away some time previously. Dave asked her to tell how she had met him, a story apparently involving a pigeon. Instead, Clara's gran told a different story, about seeing him standing on a pier so long ago and never wanting him to change. She absentmindedly played with her ring while doing so, and sadly smiled. After this, she received a tearful hug from Clara; her story reminded Clara of how she felt about the Doctor. (TV: The Time of the Doctor)