Ahoy, Karen!
The last day onboard the
Disney Magic is still a morning to enjoy onboard. I think the best way to have a pleasant end to a wonderful vacation is to still enjoy disembarkation day leisurely. If the ship returns to the Port of Miami and is cleared for disembarkation at around 7:30am (barring no delays), you'll need to be one of the first few passengers off the ship to make it to the airport on time. This would mean, you'll need to carry your own luggage off the ship and pre-arrange for private ground transportation from the Port of Miami to the Airport. There will be taxis, but imagine if there are other cruise ships arriving all at the same time that morning.
If you've got about 30 minutes of travel time from the cruise terminal to the airport, you still need to allow some time for US Customs clearing time, traffic, as well as airport check-in and security gate waiting time. I think it will be cutting it close -- especially, if you are traveling with children. I'm sure it is do-able, you just have to hustle and rally the troops every step of the way.
If convenient, I would suggest a flight departure time no earlier 12 noon on disembarkation day. It gives you a lot of wiggle room, as you get your sea legs back to land. I always feel like the family is moving a bit slow motion when everyone gets off the ship that day. I'm just worried that leading your pack through a hectic morning might wipe out all your newly refreshed spirits. And if you have to deal with a missed flight and catching an alternate flight for your whole family, that adds stress.
I hope that flight schedules work out fine for you and your family, Karen.
~ Dolly