Yes, it is called Parkinsons Disease Forum and it is for both the sufferer and the caregiver. There is also the Parkinsons Disease Foondation which is a source of good informatiom. I have Parkinsons, have been diagnosed for eight years. I will be glad to correspond with your sister if she wishes to ask questions. Look for my email address in my bio.
My DH had PD in addition to AD. I had a book about PD which included an 800 number which I called with questions. I also understand there is a new drug out to help with the tremors. Our intent was to try it, but Hank died before we could....
The severity of symptoms associated with Parkinsonn's is individual with each person and the rate of becoming more affected by the disease is also an individual rate...I was diagnosed in 2000 with a tremor in my left arm, and not much else evident to others. My neurologist prescribed an agonist medication which was very low in dosage and given 3x per day. Gradually I have lost some degree of balance although it varies from day to day, inner tremors which are still not evident to others, all over weakness sometimes, and an all over reduction in movement (slower). I also have acquired insomnia, some difficulty in swallowing sometimes, my doctor has added sinnemet to my meds although it is a weak dosage. My neurologist tells me I am doing very well and progressing slowly. I can feel the changes in my overall health and body but others do not see much of a handicap. I do not research extensively on PD because I'm afraid I would acquire some of the attributes of the disease because I would think that every ache and pain was a new symptom. I know it sounds silly but I don't go to read about any side effects or new stage until I know it is real and not my imagination. Oh, yes, I just remembered...taking a shower and washing my hair takes longer to accomplish and I eat slower, also get tired quicker and can't have the strength for picking up and carry loads that I once had.
I am amazed that I am not more involved with my disease as I have had so much added stress from coping with my husband's Alzheimer's. For five years I was on an anti depressant also but finally decided I was no longer medically depressed, only unhappy because of my husband's illness. I ceased that medication and have not had to resume it.