We cruised the Magic when DD was 8 months (Was not walking). It was great!
Be sure to get a balcony, we had a cat.7.
We took our own stroller/car seat combo (the big kind), she actually slept in that on the sun deck covered from the sun. We also took it to dinner, we had late seating.
Offer some table foods before your cruise, I only took formula. Make sure you have plenty of formula & diapers!! Very expensive.
We used the pack-n-play, it was fine. Room steward/we collapsed it during the day.
We used Flounder's, it was fine, I am a stay-at-home mom.
She became afraid of the characters as the week went on, wish we had done photos early on.
We went to Tea with Wendy, and to St. John (on our own).
I could go on and on...... Now that she is 2, I would go before the walking stage or after 3 (because of the kids clubs)
Susan