Which RCI cruise ship is best for me?

Hi I'm thinking of going to the Easter Caribbean on the Navigator, the Western on the Freedom or Oasis. Which of these ships/itineraries is better for a first timer? I have a 13 year old daughter and it's just her and I. We want to have fun and also have a chance to relax. Food isn't SUPER important but you know, we don't want it to be awful. So which one of these ships would be better? We haven't been to any of the ports so we don't care if it's the Eastern or Western Carib.