During the early years, Betty Lou was a minor character who was performed by whoever was available to perform her. She seemed to appear more in books than on the show. Apart from singing "I Want a Monster To Be My Friend" (credited, in The Sesame Street Monsters! as "Little Girl"), notable appearances included singing "Amigo" with a male friend in a sketch from the late 70s, and serving as lead singer (backed by Grover and various Anythings) for the song "Exercise" in the 1980s.
As part of an increased attempt by Children's Television Workshop to balance the number and prominence of the male and female characters, Betty Lou appeared on a more regular basis, in street storylines and not just inserts, beginning around 1993. She gained a consistent performer during this time, Lisa Buckley, and an interest in collecting dolls before fading once again into the background. Betty Lou also appeared in the video Do the Alphabet. Betty Lou has a baby sister, seen in the book Grover Learns to Read.
- Tough Pigs Book Club : The Great Twiddlebug Mystery
- Anybody Can Play (1980)
- The House That Biff Built (1980)
- I Like School (1980)
- The Sesame Street Storybook Alphabet (1980)
- What Did You Bring? (1980)
- The Count Counts a Party (1981)
- I Have a Friend (1981)
- The Sesame Street Circus of Opposites (1981)
- The Sesame Street Sun (1981)
- Which One Doesn't Belong? (1981)