Because the whole of your cruise is in the Caribbean and the outside temperature should be in the 80'Fs/26-30'C you will need three types of clothing. Casual summer wear for time during the day, something more dressy for evening wear and something for formal wear. Extras could include clothing for leaving and arriving in this country (or wherever) and maybe something for inside on the ship because the AC can be quite chill after being outside for a while. I have no idea what you have in your wardrobe but personally I would leave those jeans behind and take shorts or light slacks as there is very little place for jeans on board and they are heavy and bulky. Hope that helps, Ida.
We have been twice on Sea Princess which is one of the 'not too formal' ships!! For the evenings I usually take black jersey 'evening' trousers (easy to pack and don't crease!) and team up with various glittery and not so glittery tops, with perhaps a cocktail type dress for the formal evenings...my partner takes his black suit and wears with bow tie and white shirt for formal evenings...other evenings he wears polo shirt or short sleeve cotton shirt and lightweight trousers (grey or beige).
we have not long returned from the Caribbean and did notice it stays very warm in the evenings unlike the Med where it gets cooler.
Daytimes I wore linen/cotton trousers or skirt with strappy tops (and perhaps a loose blouse to go over the top to protect from the sun) to go ashore and shorts and strappy tops with flip flops on board the ship. Hope this helps a bit!!
I have noticed you are on the christmas cruise , so you will find alot of ladies dressed up on even he smart casual evenings. To be honest we were on for the new yearlast year and I really took too much day clothes and not enough eveing stuff as everyone seems to go to town over thechristmas and new year.....and my goodness everyone looked lovely. Day time was casual i e shorts summer dresses and such. we had our travelling clothes laundered for our return. Have a wonderful time and look after her as we are returning on 27 in barbados,< with extra glad rags bought in the sales.>.