It sounds like she may have a problem with a disc in her spine.
This is unfortunately pretty common in this size dachshund unless the breeder is being careful to breed away from it.
This site has some good info on dachshund disc disease
http://bajaokla.com/dachback/
Info on wheelchairs if surgery can't fix the back issue in your pup
http://www.dogkarts.com/
http://www.k9carts.com/
http://www.make-and-build-dog-stuff.com/dog-wheelchairs.html
It may well be the pain she was in was from a disc problem.
I hope this helps you!
Dog Expert:Rescue, Train,Breed,Care
30+ yrs dog home vet care & nursing, rescue, behavior&training, responsible show breeding, genetics