Hi Shana, I just came back from Hawaii and had a wonderful time, I have M.s. so pretty well comfined to a wheelchair!
I was on the Diamond by Princess and no probem getting around, i rented a scooter, all the staff were great and helpful! some Islands you have to go in by tender, however they look after you very well.
I am booked up next year to on the golden princess to Hawaii again and I am not worried so I am sure you will have a wonderful time. Hetty