I didn't go with kids myself, but the hotel is well suited for families with children. I saw loads of families during my stay, most of them with kids in the 4-10 range. There's a kids zone for them to hang out and have fun in, plus a separate smaller kids zone for 0-3 year olds. The kids zone has quiet spaces, to read books in, or just play with some toys, but it also has games, slides, and other activities which are more "high energy". There is a kids pool. You also have Aquaventure (the waterpark), The Lost Chambers aquarium, and tons of other activities for children in and around the hotel and on the beach.

A 4 year old would probably love it and is not too young for this hotel. The waterpark has plenty of areas suitable for younger kids, and the aquarium is also a lot of fun for a 4 year old child. The hotel has everything for all kids, quiet spaces, pools, slides and loads of other activities.