Cooper's father, Stephen Rivers, is a lawyer in Beecher Falls. He is accepting of Cooper's involvement in Wicca after meeting with members of the Coven of the Green Wood and discovering that he was already acquainted with a Wiccan, Thatcher Morris.
He and Janet separate in Through the Veil and he moves out of Welton House. In Initiation, he reveals to Cooper that he is dating Amanda Barclay, which causes some tension between them until Amanda apologizes for giving Cooper a hard time during the Elizabeth Sanger investigation and the fight to wear her pentacle at school.
Cooper's mother, Janet Rivers, is an elementary school teacher. She strongly disapproves of Cooper's involvement in Wicca, because her mother practiced witchcraft, which was a source of great embarrassment to her as a teenager. Though she did dabble in witchcraft herself for a brief time as a young girl, she ultimately turned her back on it and begged her mother to quit as well.
After she and Stephen separate, she begins to drink heavily. Cooper enlists the help of Mary McAllister to get her help and prevent it becoming a problem. When Cooper is about to be initiated, she offers Cooper a necklace that the members of her mother's coven wore to amend their disagreement over Cooper's practice.
Cooper's unnamed maternal grandmother was a Scottish immigrant who practiced folk magic from her homeland. After a teenage Janet begged her to stop practicing witchcraft, she apparently did. When Cooper was a little girl, she discreetly taught Cooper a few magical exercises, which infuriated Janet when she found out. She never taught Cooper any more magic and died a few years later.