In BVI, most if not all marinas have steps for use. I found the staff(and other sailors) especially helpful when seeking steps for my elderly inlaws.
I would be reluctant to take my elderly in-laws on a monohull. Cats being so much more stable for them (I love a monohull with rail almost in water. In-laws would not like it, and even sitting in cockpit would be a challenge, much less going to head while underway).