After hearing for years about Jenny Piccalo from her best friend Joanie, we finally got a glimpse of her in the flesh. Jenny arrived on the show in 1980 and that was where the show started its decline. While Happy Days lasted through many changes, from Ritchie leaving to The Fonz turning into a wimp, it was Jenny who wins the honor of being "The Oliver Factor". Part of Jenny's early appeal was the fact that she was unseen. We lived her life through Joanie's eyes. Once Jenny became an on screen regular, her appeal was gone.
Other characters who came close to being the Oliver Factor were KC, Ashley, Lori Beth and Heather. But Jenny wins.
Jenny Piccalo was played by Cathy Silvers, daughter of Phil Silvers. Cathy appeared on Happy Days from 1980-1983. Last we heard of Cathy she was running a catering business and seeking voice-over work.