That is quite a lot of medication, especially for a woman who is probably in her 70's.
I don't know anywhere near enough about Parkinson's or the meds used to treat it to give you my opinion, let alone an answer.
I suggest three things. As her daughter, you have the right to speak with her doctor about your concerns regarding the meds. Secondly, you could speak with your local pharmacist who is a DOCTOR of PHARMACOLOGY and get his learned opinion on your mother's med load. And lastly, you could go to our Parkinson's Forum and speak with the folks there. They will have much more information than I do about medications and can probably tell you if they think your mother is being over-medicated.
I do know how hard and heartbreaking this is for you. I wish you the best and urge you to take care of yourself.
Peace
Greenlydia