I was watching a movie I found interesting. It was about a girl who does not fit in with the other kids and because her parents are poor and can't afford to but her fashionable clothes but her life quickly takes an unexpected turn.

It might be the movie 'Pretty in Pink'. See if it matches your memory by following this link: http://www.imdb.com/title/tt0091790/

No its not pretty in pink. Molly ringwald wasn't in it. And it was made in 1993.

'Clueless' with Brittany Murphy as the girl who can't afford the fashionable clothes... 1995?

No its not clueless either its about a little girl around 7 or 8. her dad is a farmer and not a very good one and that's why they are poor. The girl goes into church with her dog while wearing rags and everybody in the church stares at her.

Little Heroes (http://www.imdb.com/title/tt0104739/)?

That might be it.