Moran played the younger sister of Ron Howard on Happy Days, which aired from 1974 to 1984. She was 14 when she began the show and the role would be the pinnacle of her career. She co-starred with Scott Baio in a spin-off series called Joanie Loves Chachi for one season, from 1982-1983. Moran started her career as a child actor with roles on The Courtship of Eddie's Father, My Three Sons, Gunsmoke, and The Waltons.