Lasting Power of Attorney or Independent Mental Capacity Advocate are two. Without knowing the complete situation it is difficult to advise. Speak with family, doctors or others involved. Get advice from an attorney if needed.
Well that depends - physically or financially? You will need a Power of Attorney to make legal or medical decisions. If you will be physically taking care of yr parent you could talk to their Dr, and also check to see what if any certifications may be required ie first aid etc. having had a sp needs child I appreciate the love & respect needed to do this yrself. Just remember - take time for you - No Matter What. & don't feel guilty about it. Best of luck. Oh yeah support groups actually do help esp for newbie caregivers )