Answer: Mia Sara
" Ferris, please. You've gone too far. We're going to get busted." - Sloane
She was perhaps the thinnest character in the movie, as she had little scope to shine. Ostensibly, she was Ferris' girlfriend - there was a scene where Ferris talks of marrying her, but they only share a deep kiss when Ferris was disguised as Sloane's father! There is not much interaction between them and then there is this scene where Ferris was cutting through neighbours' yards, trying to beat his parents home, yet he stopped to introduce himself to sunbaking girls - a sleazy move.
Sloane had a couple of moments in the film: When she pseudo-flirted with Ferris' dad in an adjoining stationary cab and also when Cameron thinks Ferris had ditched them at the Parade. Sloan calmed him down indicating she was a solid friend.
Sloane's role appeared to be the middle ground between the extreme guile of Ferris and the self-deprecation of Cameron. She was not above skipping school - she spins a tale about her grandmother dying, but she was otherwise nice throughout the movie.
Perhaps, tellingly, Molly Ringwald, one of Hughes' favourites, wanted the role of Sloane but Hughes refused, saying the role was too small for her.
Sloane was played confidently and competently by Mia Sara, who had a solid resume for someone who was not in the spotlight much. She was married to Jason Connery in 1996. The couple divorced in 2002 after having a son in 1996. She had a daughter in 2005 with puppeteer Brian Henson. They married in 2005. She also has a pilot's license.