Heap64 wrote:
I have no personal experience with these, but I have heard people say they helped their dogs.
http://www.thundershirt.com/
That's what I'd try next.
I'd also work on getting her really acclimated to the travel trailer. Let her hang out in it (with you) while you're at home as much as possible.
On trips bring along a couple of her favorite toys, a familiar blanket or bed, etc. Also, when you leave her in the TT make sure you leave on something for white noise. We leave the TV on for our dogs, and sometimes we leave the AC fan in the "on" position so it will run constantly.