Penny was known in her family as"the bad one"... because not only did she walk on the ledge of her family's apartment building, but she snuck into the movies as a child and even dated a guy named"Lefty." She attended a private girls' high school in New York and then went to the University of New Mexico for 2 1/2 years. There, Penny got pregnant with daughter, Tracy Reiner, and soon after married the father, Michael Henry, in 1961. The couple divorced two years later in 1963. She worked as a secretary for awhile. Her first film debut came from her brother Garry Marshall, who put her in the movie How Sweet It Is! (1968) with the talented Debbie Reynolds and James Garner. She also did a dandruff commercial with Farrah Fawcett - the casting people, of course, giving Farrah the part of the"beautiful girl" and Penny the part of the"plain girl." This only added to Penny's insecurity with her looks.　　She then married Rob Reiner on April 10, 1971, shortly after getting her big TV break as Oscar Madison's secretary, Myrna Turner, on The Odd Couple (1970). She also played Mary Richards' neighbor, Paula Kovacks, on Mary Tyler Moore (1970) for a couple of episodes. However, her Laverne & Shirley (1976) fame came when her brother needed two women to play"fast girls" who were friends of Arthur Fonzarelli and would date Fonzie and Richie Cunningham on Happy Days (1974). Penny had been working on miscellaneous writing projects ("My Country Tis Of Thee", a bicentennial spoof for Francis Ford Coppola and"Paper Hands" about the Salem Witch Trials) with writing partner Cindy Williams. Cindy happened to be a friend and ex-girlfriend of Henry Winkler's, so Garry asked the two to play the parts of these girls. The audience saw their wonderful chemistry, and loved them so much, a spin-off was created for them.