In mythology? Simply, they were not. Cronus was swallowing his own children out of fear of being overthrown by one of them. Rhea had given him silent backup to it, unless she decided it's enough for her. Then, she saved that one son, which became Zeus. So: Cronus was a monster, not a father. Rhea was just one of those constantly beaten women who agree with everything with their husband, because she fears him.