Princess are my favourite cruise line, and ive been on most of them ( and worked on quite a few), great for families or couples, the emerald is a gorgeous ship im sure you would have a wonderful time, we did ruby princess grand med in june, 12 nights barcelona to venice and that was fantastic, highly reccomend it.
Princess is excellent for families. We have cruised many times with them and the children have never been bored! I would recommend you opt for personal dining and then that way you can eat where and when you are (or the kids) hungry, and don't have to be tied to set dining room sittings.
I think Royal Caribbean and NCL are better.