Frankie is a woman who Charlie and Alan Harper met in the car park. She's the mother of Joanie.
She makes her first appearance in "Round One To The Hot Crazy Chick" as a crazy chick thrashing her shrink's car. After Alan accidently turns on the car's alarm he and Charlie are forced to take her with them. In the next episode, it is revealed she married a very rich person named Brad and his parents hated her because when she met Brad he was on the road to becoming a U.S congressman while Frankie was just "on the road" and they hated her much more after part of Brad's trust fund has been used to finance her recording career. Then Brad died and his parents have been trying to get custody of Joanie away from her. She later goes to Seattle to her brother and sister-in-law to build her life over again.