Think twice before leaving your precious cat in a caravan. If she shoots out, when you open the door, you have lost her. So if you need some air, tough. Everything must be shut all the time. If you leave a window open (which you will need to do in a hot summer) she may get out and you have lost her. And do not leave a cat in a hot caravan while you are out all day on holiday. And think of the smell from the litter tray in a hot summer. If you put her on a lead, she will not like that. And cat collars are designed so a cat can slip her head out if she gets caught somewhere, so she will slip the lead and you have lost her. And at the end of the holiday you will have to drive home. Without her. If there are no houses near the site, she will not find another home. She might not even if there are people living nearby, she may starve.
I take my cat to the cattery, a beautiful place. Maybe you could find a nicer cattery, always ask if she can be placed away from other cats if she is timid. She spits and snarls, but when I go to collect her, she is peacefully sleeping on her ledge or in her cat basket. (Always take her basket and toys when you leave her). She will be fine in the cattery and more importantly safe. Please.