I don't think any actor should be considered a role model. That's not what they signed on for, and it is a tremendous burden to bear. Even in being normal for their age, they are going to alienate fans if they are considered a role model.
Example: Johnny Depp is an actor but never has been a role model, which is good because he was a wild child. If he would have been a role model, many would have condemned him for acting normally for him at his age.
No kristen isnt a good role model. Anyone who is accused of doing drugs shouldnt be a role model.