My niece is always clearing her throat often more if nervous or excited we do have a family history of turrets and adhd should we be concerned?

Throat-clearing : Can be a vocal tic. Tourette syndrome diagnosis requires multiple motor tics & at least 1 vocal tic for at least a year, with no tic-free periods >2 mos., but females with ts can have anxiety &/or adhd without full-blown tics. It bears watching by her pediatrician; if it impacts her social, behavioral or educational functioning, she may need referral to a specialist.

Not necessarily.: You are describing a simple tic which is relatively harmless and often more pronounced when nervous or excited. Tics can occur with adhd and even obsessive compulsive disorder. If any of these are concerning or causing difficulties in day to day functioning it is worthwhile to see a psychiatrist for an evaluation and treatment recommendation.