welcome JAM's Mom

honestly, only a developmental pediatrician and/or a neurologist would be able to make an accurate diagnosis

Psychologists arent really the one's who are trained or qualified in dx neurological disorders, which is what Tourette Syndrome is
They can help a lot with therapy (like cognitive behavioral therapy for OCD etc) and with other aspects of psychological symptoms, and behaviour , but may miss some of the finer clues as to neurological issues

when my son was first DX, by a developmental pediatrician (and later confirmed by a neurologist) he did not, to my observance, tic at all during the meeting. But the doctor was able to see certain things by observation and by the questions he asked.