Shuttles and a car seat?

[jgmklmhem]

We are going to DL but I thought I would solicit info here as well. In general how do the shuttles work with regards to a car seat. We have 2 adults a 5yo and a 20 month old going on our trip. According to our shuttle service the 20mo is free. We will have her car seat because she will have a seat on the plane but we will not necessarily have our 5yo's booster. I guess my questions are:

1) Even though we will not be paying for our 20mo on the shuttle will we be able to use her car seat or will we just hold her or will we have to buy a seat?????

2) Will our 5yo need her booster seat?

Thanks for the help!