Ahoy Maria Fernanda!
Welcome to the Disney Parks Moms Panel! Great choice with the Disney Fantasy! That is my favorite ship! My first Disney Cruise, my daughter was 2 years old and there were some Port Adventures that she could do and some she couldn't. When you look at the list of the Port Adventures, you will find that each activity lists the price points by ages. If an activity lists: "$0.00 (ages 0 to 3)", this means that you can bring the baby at no cost. It will also state "All Ages" if this is an activity that you can bring your baby.
For example, if you are stopping in the Bahamas, there is a Port Adventure in Nassau for "Atlantis Aquaventure" Here is what is listed for the activity:
Port of Call
Nassau, Bahamas
Prices (Subject to change without notice)
$204.00 (ages 10 and up)
$146.00 (ages 4 to 9)
$0.00 (ages 0 to 3)
Activity Level & Duration
Active
4 to 6 Hours
Experience Type
Beach and Water Adventures, Sightseeing
Age
All Ages
Since you are sending us this question from Mexico, I wanted to also let you know that
the Disney Parks Moms Panel is now answering questions in Spanish! Please feel free to check us out and if you have any friends or family that would like help planning their Disney vacations in their native language, send them our way as well! Maria Fernanda, it has been my pleasure assisting you! Thanks for sending your question to the Disney Parks Moms Panel!
Bon Voyage,
~Yael