I would definitely recommend that your daughter make an appointment with a pediatric ENT (or general ENT that sees children) to be evaluated. There are many different things that can cause throat clearing. Sure it is a possibility that frequent throat clearing could be the early manifestation of a "tic" disorder like Tourette's syndrome, however this is definitely not the most common, or even a relatively common, cause. Much more common would be a problem like laryngopharyngeal reflux (LPRD) which is a condition in which reflux (sometimes not enough to actually give a heartburn sensation) comes up from the stomach through the esophagus and into the back of the throat. The top of the esophagus is directly behind the larynx (voice box), and if even a little stomach acid makes it into the larynx it is very irritating. This can give the sensation of globus (something stuck in the throat) and cause frequent throat clearing. This is one of the most common causes of throat clearing when patients present to an ENT (Ears Nose Throat) doctors
office. Also behavioral patterns can cause throat clearing which causes continued irritation within the larynx and is a repetitive cycle. I would definitely recommend that you take your daughter to an ENT's office first.