Best known for portraying Valene Ewing on thirteen seasons of Knots Landing; she later reprised her role on the series Dallas in 2013.
She decided to pursue a career in acting after interviewing actress Julie Harris at age fifteen.
Seh was named after Joan of Arc because her dad knew she was going to be a star.
She married John Marshall in 1966; the couple welcomed a daughter, Vanessa, in 1969.
She starred with Alec Baldwin in Knots Landing.