She played in movies for teens as the cute but thougf tom boyish girl.she had short hair nice lips like julia roberts...

There are a lot of Actresses that could be who you're thinking of but the one I think comes the closest is Anna Chlumsky.

She played Vada a tomboy like girl in My Girl.
Jody in Gold Diggers: Secret of Bear mountain.

Hello:

I think you're talking about Hilary Swank.

excon

Could also have been Christina Ricca?

Could it be Joyce Hyser. She was in that movie "Just one of the Guys" 1985. Where she dresses up as a guy to get a story for the school paper to win an internship.