A 12:10 flight out of Miami is plenty of time. We got off the Spirit in April over Easter and had a 9:30 am flight out of Miami. We made it with an hour to spare. Normally, I would never book a 9:30 am flight, but the only other option was the 5:30 pm flight from Miami to Chicago--then another 3-hour drive home and we had to work the next morning. We took the chance and made it. Luckily!