Mumsnet hasn't checked the qualifications of anyone posting here. If you have medical concerns, please seek medical attention; if you think your problem could be acute, do so immediately. Even qualified doctors can't diagnose over the internet, so do bear that in mind when seeking or giving advice.
Do you keep the windows of the car wide open? That used to help me when I was chronically car sick as a child.
Do you make sure she doesn't look out of the side windows of the car? - she should look straight ahead concentrating at a point in the distance. It does help. Or is she not old enough to follow that instruction?
Helps to sit in front passenger seat. Perhaps you can bag the seat near the driver on the airport transfer journey.
I was like this from a young age and still now am a dodgy passenger to have on a long journey. The bands really helped me so could you try bribery to get her to keep them on? Also sitting in the front defintiley helps, looking straight ahead like hmc suggests - my mum used to say follow that car/line of street lamps, not eating or drinking on a journey although sips of water can help.
My ds(7) has suffered badly since he was 1. He can be sick on a 10 min journey ( and is sick on planes and boats). I know a lot of things which help but nothing than can stop it sadly.
How old is your dd? - can you distract her with games yet (eg I-spy, car counting etc) Anything to keep her looking out the window. Avoid toys books etc for the same reason. What about a personal stereo with songs or stories? Try and sit at the front if its a coach. Have a container handy (just in case) - we use a tupperware container.
Another tip is to try and put bags under her feet so that she can rest her legs on them rather than letting them dangle in mid air as this adds to the feeling of being on a fun fair ride IYKWIM. I'll let you know if I think of any thing else. You have my complete sympathy!
You could try a homeopathic remedy called Nux Vom. Give it to her about 15 min before a trip and repeat during the trip if it's a long journey. I obviously can't make any garauntees but at least homeopathic remedies are really safe and easy to take so you shouldn't have any anxiety about giving them.