Morgan Brittany (born Suzanne Cupito) is an American actress. She is best-known for her role as Katherine Wentworth, the scheming younger half-sister of Pamela Ewing and Cliff Barnes, on the prime-time soap opera Dallas. Career Early child career Los Angeles-born Suzanne Cupito began her acting career as a child under her real name. She appeared on many programs in the 1950s and 1960s, beginning at age five in a 1957 episode of the CBS television network anthology series Playhouse 90 (or at that same age in an episode of Sea Hunt). In January 1960, she displayed her talent as a ballet dancer on The Dinah Shore Chevy Show. Three months later, she followed that up with her first of three Twilight Zone episodes, uncredited as a little girl in "Nightmare as a Child". She also portrayed Sissy Johnson in the season four episode "Valley of the Shadow" and the vicious brat Susan in the season five episode "Caesar and Me". She was featured in the musical film Gypsy (1962), as Baby June. She appeared in the episode "Daughter for a Day" on ABC's My Three Sons (1962) as Jeannie Hill. She appeared in the episode "Daddy Went Away" on CBS's Gunsmoke (May 11, 1963) as Jessica Damon. She appeared uncredited in the birthday party and school house scenes in Alfred Hitchcock's The Birds (1963). In 1963, she played "Winter Night" in the episode "Incident of the Hostages" of Rawhide. In 1964, she starred as a blind girl named Minerva Gordon in a two-part episode of The Outer Limits, "The Inheritors", appeared in the Western film Stage to Thunder Rock. In 1966, she appeared in the series finale of the Western Branded, playing an orphan named "Kellie" in the episode of the same name. She was part of the ensemble cast in the film Yours, Mine and Ours (1968), which is led by Lucille Ball and Henry Fonda. She also appeared in the season eight premiere episode of The Andy Griffith Show titled "Opie's First Love" as Mary Alice. She appeared in two episodes of Lassie, "Lassie and the Swamp Girl" and "Little Dog Lost" as "Mattie" in the mid-1960s. She followed that up with appearances on Gunsmoke and other shows. At the age of 15, after appearing in Yours, Mine and Ours (1968), her childhood career came to an end and she concentrated on getting her education at Cleveland High