My mom's going to bring a full-size suitcase, as she lives north of Miami, while I am only flying with a carry-on and backpack. So, she will probably use a large shoulderbag or totebag to contain her purse, valueables, prescriptions, etc. and she should be ok whether we han gout on Lido or walk about the ship (most likely) before we can go to the cabin and unpack.
I will put my rolling carry-on under a cabin bed and if it gets taken, it will just have clothing in it. Nothing I can't replace in Key West. Then I can just wear my backpack with my netbook, travel docs, purse, and other critical items while we check out he ship!