The reason for not visiting the doctor may be worsening of her mental illness. Such patients frequently refuse doctor visits which is one of the signs of worsening of the illness. Later they may refuse to eat food or take bath or participate in activities, sleep less, become irritable.  Sizopin should not be stopped abruptly without the advise of a doctor.  Please take her to her treating psychiatrist/consult someone online. 

The reason of not visiting a doctor might be increase in psychotic symptoms , in that case after assessment increase in dose can be justified and helpful