1) How is she getting 325mg of stalevo? This is not a standard dose. I would assume that she is taking 125mg pill + 200mg pill. This would not be advised since she would be getting 400mg comtan at a time, instead of the recommended 200mg. By replacing the stalevo with sinemet and comtan, she is now getting 200mg of comtan which might be helping her.
2) If she still has hallucinations, something like aricept might be helpful. This is an Alzheimer medicine, but it works very well for PD hallucinations.