Mary Ann Petterson is portrayed by June Squibb; she is Melinda's grandmother and, like her, bears the gift of the ability to speak to the dead. Mary Ann supported the idea of Melinda learning more about her gift, but her daughter Beth refused to allow her daughter to do so, leading to a fall out between Mary Ann and Beth.
Powers and Abilities
Mediumship: Like Her Family, Mary Ann is able to see and communicate with spirits and helps them cross over into the light, she trained Melinda to use her ability and gave her knowledge in spirits and how to help them.
Beth makes a total of 7 appearances throughout the first three seasons.