Katry, if you want to do the three day, go for it. We have the 4 day booked on Caribbean Princess, and they are offering a lot of the people who are already booked on the 4 day a special if we would switch to the 3 day, they would give us half off, also a on board credit, and a balcony cabin if available. So I wouldn't book the 4 day, because all 3 of them are booked solid. Good luck with whatever you choose. And an early congratulations on becoming a grandma! You'll love it!