A school can suspend students for acts which threaten others, which disrupt learning, or which represent infractions of school policies. If  the school had an anti-profanity policy in policy, or some other policy which would apply, they may have the right to suspend her. If the suspension or other punishment, however, seems or becomes disproportionate to the offense, then you may able to challenge it (students have a right to an education and to due process). If it seems to get to that point and you cannot make headway on your own (e.g. by speaking to district-level supervisors), you may wish to retain an attorney to help you.