As others have said, some infants do well with characters, others not so much. Face characters, like the princess meals, should be ok because they can communicate with the baby a little easier. If you want to try meals with other characters, don't book them early on in the trip. Give the baby a trial run or 2 with M&Gs and see how they do. If it's a success, keep the ADRs. If it fails, cancel the ADRs before the date you have the scheduled for (you can cancel up to 11:59 PM the night before a character meal and not get charged).