Karen, the only thing I would add to the above replies is that some ships have a guest laundry, and if yours does, you could pack half a week's daytime clothes instead of a full week's. If the ship does have a guest laundry, it will also have a soap dispenser and a change machine, so you don't have to worry about bringing detergent.
Some people will think I'm nuts for doing this, but if I'm on a ship with a guest laundry, I wash all our dirty clothes on the last afternoon. It might take a couple of hours of pool time, but it's a great feeling to come home from a wonderful vacation and not have to deal with a mountain of laundry!
Have a great cruise --