Granted. But the suspension, apparently, was for violating the smoking policy. The kids were aware of the smoking policy as outlined in the rule book, and by signing the book they agreed to abide by those rules. But it would be difficult to abide by rules that you were not even aware existed. Only administrator's knew about this other rule. Hence, to be punished for a rule that you were not even aware existed, I believe, would be unfair and worthy of a fight.
Do I think Saraaras will win against the administration? Probably not, but attorneys win contract cases based on errors and omissions in contracts....so I think she should win, based, at least, on the facts given in the original post.
As a side note, I am also opposed to out-of-school suspensions, because they are ineffective and take away from learning. What would be far more effective would be to have Saraaras accompanied to and from classes for 10 days by her mother, so she could not leave the campus area to smoke (and leaving the school's campus, I feel, is far more serious than a smoking violation).