Jannaw,
Check to see if you can reserve an electric cart,
or a 'hoveround' maybe even rent onre to take with you.
They'll fit anywhere, and they have elevators on those cruise ships. You can leave it in the hall, if it won't fit in the cabin.
Just call ahead to the cruise line and tell them you need one, or are bringing one. It'll save walking and then when you get out of it in the hall, you can use your cane