She maybe having an episode of psychosis. Psychosis usually comes in 2 "flavours". Auditory or Visual. Usually for Auditory, the sufferer may experience / perceive loud 3rd parties speaking / shouting in their own head which are not present. This is different from one's inner thought processing or aka mouthing to own thoughts.
From what I observed this is unlikely to be Tourettes syndrome. People with this syndrome have verbal tics when communicating with others. For her case, it seems that she's speaking with someone, hence the outlandish body and hand gestures. It is highly unlikely she has both Tourettes and Schizophrenia. Again, I am not a mental health professional. This is just my opinion and experience based on some previous encounters
Psychosis is a classic symptom of schizophrenia. If this is officially diagnosed by a psychiatrist. Sufferer needs to be on lifelong medication to curb the symptoms. As schizophrenic people can be VIOLENT and pose a danger to oneself and others. If anyone experiences such episodes, please kindly seek immediate medical treatment immediately.