Nana James is the Grandmother of Mark James and the mother of Sheriff James.
Mark's Nana ensures that they are well fed, happy and safe. She sits in a chair at the bottom of the stairs with one eye on the front door and another on Mark's truck, when her son orders Mark to stay at home, the same night that he is caught breaking into his office and John returns to Paradise.
She has a playful relationship with Mark and tells him that the James men have always been a stubborn brood and that he was no exception. Mark acts hurt, as if he's been wounded him with an imaginary bullet and she chuckles to herself.