Mary Dennis is a widow, having survived her husband Sam. She taught Bo that premarital sex was evil and often took Bo to church.
After Bo accidentally killed Kyle Williams the night she lost her virginity, she told her mother what had happened. Being unaware of the existence of Fae and her daughter's true nature, Mary believed Kyle's death was caused by religious transgression. Mary called Bo a "devil child" and a "monster."
Mary's inability to be compassionate — coupled by the trauma of killing Kyle when her succubus need to feed from chi finally emerged, and not knowing what she had done and why — caused Bo to run away from home and stay away for more than ten years.
Bo returned to visit her mother in order to resolve their issues. It was revealed that Mary had begun to be afflicted with early stage dementia during Bo's absence and had no recollection of the night Bo left.
Bo confronted Mary about why she ran away, confessing to her mother that she was Fae, and the two were able to reconcile their differences.
She is a deeply religious, conservative woman.
- Bo: Her daughter.
- Sam Dennis: Her late husband and Bo's adoptive father.