help? what can i do to improve this.

Your thesis could be better stated with two changes. First, move "to parents" to become an introductory clause. Right now, this modifying clause comes between the subject and its verb, thus confusing the reader. Not all such structures are wrong or confusing, but in this case it is.

"To parents, role models are people who demonstrate positive actions."

Second, you may wish to look for a broader, more accurate phrase than "positive actions". I would suggest "positive values" because demonstrating positive values also encompasses taking positive action. Also, an action is not something you demonstrate but something that is undertaken.

"To parents, role models are people who demonstrate positive values."  Or "To parents, role models are people who take positive action."