Sarah Williams (whose last name isn't revealed in the movie), being the protagonist of Jim Henson's film Labyrinth, is the love interest of the antagonist, King Jareth. She is the older teenage half-sister of baby Toby whom she wishes away because of her anger.
However, with the help of Hoggle, Ludo and Sir Didymus, Sarah is able to save Toby by declaring that Jareth has no power over her and is returned to her room and Toby to his cot.
Proof Sarah Counts
According to an exaggerating story Sarah tells from her favorite book of the same name as the movie to her bawling baby half-brother, the King of the Goblins had fallen in love with the girl in the story.
At one point, Jareth tries to distract Sarah with a dance, showing that she is dancing with him.
In the original screenplay for the romantic ballroom scene, Sarah was going to kiss Jareth. This was cut for reasons unknown.