T.D.
You guys will love it. We just moved back here after living on Florida's west coast for 3 years. The most important thing is shelter from the sun... you will need a good umbrella or other shelter for her and baby sunblock (they make tear-free so it doesn't sting her eyes) and bottles of water.
Be prepared for sand to be EVERYWHERE. The fine powder sand sticks to everything. Park near a wash station so you can rinse off before you change her diaper and get in the car!
Buckets and shovels are always fun, she will like filling and dumping the buckets. Ryan used to love walking along the shore where the water would barely lap up on his feet. The noise can be a bit frightening at first for them but they get over it. :o)
It's a beautiful time of year there right now. You guys will have so much fun.
t