The things in your favor, Ft. Lauderdale is not an extremely busy airport and Port Everglades is no more than 10 minutes away. Things not in your favor, weather, plane being late for depature, lost luggage. If all goes well, you'll make it. If not, you'll be flying to Nassau. Please read and remember what LisaP wrote, take a cell phone, the number of the cruise line, the number of the airline. Your best bet would be some type of insurance, but that is totally up to you.
Good luck and best wishes!