We are taking the carseat for my DS who is 2 and will be using it on the plane and in the rental car, but we are unsure about the booster seat for DD. She is 6, 47-48 inches tall and about 48 pounds. In Ohio she has to be in a booster seat, but I'm not sure about Florida. The one she is in now is the kind with just a bottom piece. She was too tall and really uncomfortable in the ones with the back on them, so we used this instead. Personally, I'd rather have her in it for the little bit of added safety. But DH is being anal about how much we have to take to the airport. So far we have 2 big suitcases to check, 2 duffle bags to check, a backpack and another duffle bag to carry on, two kids, a stroller (to gate check), the carseat, and possibly this booster seat!
Help!!!

Help!!!