This is her first carride and it will be very stressful for her. Expect that she will have and accident in her carrier. Do not discipline her for this. Just clean it and ignore it. You may give her water if it is going to be a long ride.
Heat prostration sets in very quickly in a stressed animal.
Talk very gently and calmingly to her. Put her in the cage with her litter and some water. Wait about a half hour before giving her food, and then just a little at first until she calms down. She misses her momma and her siblings. She is in a strange place with strange people and she will be very afraid.