In the film, Linda was portrayed by an unknown actress in the photos and clippings that appear in Sarah's room.
Linda also appears in the film's novelization, as well as its manga sequel Return to Labyrinth. Her appearances in both are brief and indirect, primarily serving as explorations of Sarah's perception of her.
Role In The Film
A scrap-book in Sarah's room features multiple clippings and articles that feature a woman called Linda Williams, who is revealed in the novelization of the film to be Sarah's absent mother. Clippings referring to Linda are also stuck to Sarah's vanity.
While she is never referred to explicitly in the film, the fact Sarah keeps a scrap-book dedicated to clippings relating to Linda's career and personal life indicates that Sarah holds her in esteem. As well as featuring in the scrap-book and in the clippings tacked to Sarah's vanity, photos of Linda can also be seen on the walls of Sarah's room.
The magazine clippings featuring Linda largely appear to be taken from theatre magazines such as Playbill, which features Linda on the cover. The headlines of the clippings include 'A Theatregoer's Notebook', 'Linda Williams: On-Off Romance Back Together?', 'Williams: Love, It's All Over' and 'The Onstage Kiss'. The clippings titled 'On-Off Romance' and 'The Onstage Kiss' both feature Linda with her lover Jeremy, who is only named in the film's novelization.
Appearances In Other Media
Linda's character is significantly fleshed out in the film's novelization, which goes into some detail describing her lifestyle and relationship with Sarah. Linda is described as a woman "who could shout and laugh and hug you and slap you all within a minute or two." The novel indicates that Linda has a quick temper, referring to the fact that she and Sarah often get into arguments but always work things out in the end. Linda and her boyfriend Jeremy are shown to live a luxurious, fast paced life consisting of meals at expensive resturants, visits to country clubs and theatre performances.
The novel states that Linda gave Sarah the music box featured prominently in her room. In the novelization, the music box plays Greensleeves instead of As The World Falls Down.
The novel also confirms that Linda earns her living as an actress, and by referring to a photo of a ten-year old Sarah with both her parents indicates that Linda and Robert separated in the early 1980s.
Return To Labyrinth
In the fourth volume of Return to Labyrinth, Linda is featured in three distinct scenes with a young Sarah. The first is a dream of Moppet's that features Linda, Robert and Sarah, whose appearance alternates between that of a teenaged Sarah and Moppet herself. Linda is shown encouraging Sarah's passion for theatre, and tells Sarah of her plans to take her away so she can learn to be actress. When Sarah questions Linda about her relationship with her father, Linda replies that she and Robert are still happy together and in love.
In the second sequence to feature Linda, an adult Sarah witnesses a grotesque puppet show where caricatures of herself and her family appear. In the show, Linda is shown to callously abandon Sarah to run away with her boyfriend Jeremy.
The final scene to feature Linda is a continuation of Moppet's dream, and shows Linda becoming gradually more frustrated with Sarah/Moppet as she rapidly recovers the painful memories taken from her when Mizumi split her soul. In this scene, it is revealed that 'Moppet' was the affectionate nickname Linda had for Sarah when she was a child.
The veracity of all of the scenes in Return to Labyrinth that feature Linda is highly dubious, with the first and third taking place in a dream of Moppet's and the second being a puppet show put on by Jareth to stir Sarah's memories of him.