Despite taking place during the Great Depression, at its core, the classic TV series The Waltons was all about love. From the relationships among family members to their love stories throughout the course of the show, there was always a focus on romance and matters of the heart. So it shouldn't come as a surprise that John-Boy, played by young heartthrob Richard Thomas, brought his real-life girlfriend Sian Barbara Allen to play his love interest on the series.
Reading, Pennsylvania native Sian Barbara Allen had established a steady acting career for herself with roles on O'Hara U.S. Treasury, Owen Marshall, Counselor at Law, Alias Smith and Jones, Gunsmoke, Bonanza, Love, American Style, Columbo, and more. In 1972, she was cast in a horror film called You'll Like My Mother opposite Richard Thomas and Patty Duke, in a role that earned her a Golden Globe nomination. She and Thomas fell in love on set and soon after, she was cast in the role of Jenny Pendleton on her boyfriend's hit television series.
The character of Jenny was introduced in the episode "The Love Story," where she and John-Boy discover first love while Jenny stays with the Walton family while her parents are out of town. Granted, the couple didn't ride off into the sunset which is why Allen didn't become a main cast member. Though Jenny did return the following year to appear in "The Thanksgiving Story" which was towards the end of Allen and Thomas's real-life relationship.
A tabloid from the 1970s wrote a dramatic article about their affair, though no one is quite sure why things didn't work out. The full article can be found at All About the Waltons.
"The photos you see on these pages were taken during the last few happy weeks of the beautiful love affair between Richard Thomas and Sian-Barbara Allen. Lately, they have been seen dating others, but we feel sure that when Richard Thomas' book of poetry is published this fall, several of the verses will memorialize the happy times he shared with Sian-Barbara. It was well-known that the two of them shared an intimate and loving relationship, though each declared openly that they wanted to further pursue their careers before marriage was even considered. Some friends privately asserted, however, that they thought Sian-Barbara would have been only too happy to least partially give up her career and settle down as Mrs. Richard Thomas."
A quote from Allen's mother, who claimed that she absolutely loved Richard Thomas, was even included.
"I liked him very much. He's so sweet and he's got so much charm and vitality. He wakes up that way...I can't think of anything I don't like about Richard," she said.
Regardless, the relationship wasn't meant to be and the two actors fell apart, pursuing their own careers. Allen went on to appear on numerous TV shows including Marcus Welby, M.D, Ironside, The Rockford Files, Hawaii Five-O, The Incredible Hulk, Cagney & Lacey, Police Story, and Kojak as well as the TV films The Family Rico, Scream, Pretty Peggy, The Lindbergh Kidnapping Case, and Smash-Up on Interstate 5. Allen even appeared in a few feature films including Gregory Peck's western film Billy Two Hats.
Her very last acting role was in the L.A. Law episode "Whatever Happened to Hannah?" in 1990 before she decided to officially retire from acting. Allen moved on from Thomas and married Peter Gelblum in 1979 with whom she welcomed a daughter.