We had a dachshund once. She had separation anxiety when we were gone. Tried a wire crate - didn't work. Got her a vari kennel, and she was fine. Seems that breed likes the closed in feeling - gives them more of a sense of security.
I'd also recommend the Thundershirt - they've worked well for me on numerous dogs.
You can also try some Bach Rescue Remedy. It's not a drug and helps calm the dog.
I agree with the folks who recommend letting her spend time in the trailer with you, when it's at home to get her used to it.
We also close the blinds and leave the tv on when we leave them in the MH and we go away. The tv helps to mask outside noises.
Good luck.