I would look at getting her seen by a MDS (Movement Disorder Specialist).

Yes, too much Levadopa is bad as too little. Fine line on the medication. Too much as you do become schizophrenic.

National Parkinson's Foundation is a fantastic resource, they are down in Florida, but the nursing staff accepts calls from all over the USA. They shut down for a week for July 4th vacation, but excellent resource.
*edit*
I realize there is many other issues that could be at play, I am just a person with Parkinson's.

With sinemet, slow changes are good. You do not want to increase/decrease rapidly. A fellow PWP would forget to take her medicines (she felt great and was convinced she did not need them... basically started hearing voice, and Police would be called... they tossed her into the Psych ward, no Parkinson's meds... but Psychiatrist would start giving her drugs to calm down the voices, and took her husband about a week to get her released... then about four week recovery to get back on Sinemet and her old self). This one reason I am a strong advocate as many Psychiatrist do not see PWP in the course of the day, but a MDS will deal with just movement disorders (often it can be four to six MONTHS for that first visit... good ones are booked up!). When I am "on" you would be hard pressed to have any idea I had Parkinson's, yet when "off" I appear drunk with loss of balance and slurred speech. I do wear my bracelet when traveling, but not around town.

John.. I take 8 -- 4 time 2 - 25/100 daily -- and 4 times Comtan 200mg daily. This is equivalent to Stelevo (I take Generic, so copay is around $20 a month/Stalevo would be $200/Rytary around $600 with my insurance). I'm doing good with the genetic Sinement and Comtan (just occasional hallucinations, but pleasant ones). Worst part is I typically sleep three hours a night, out like a light at 10pm.. awake at 1... but rest in bed till three so I am not so exhausted.

Ashley... Best of luck to you and your wife.