In my limited experience, Papuans are one of the "best" feeders out there. I would chalk this up not to the prey items (in the wild they are incredibly opportunistic, and have been found with literally everything possible in them) but to stress or medical ailments. I would dim the lights, and leave absolutely alone, except to provide fresh water every few days. Don't even mist (if thats how you keep your humidity up) just provide a box with sphagnum moss or the like. Leave her like that, and try again in two weeks. While you are giving her some space, bring a fecal to a vet, as there is an equal liklihood (if she looks real thin) that the stress of shipping/transport has weakened her (usually strong) immune system, and her parasite load is too high. Many people have commented on the incredibly high loads these pythons can carry, so there is a good chance that a compromised system allowed for them to get out of control. If that is indeed the case, then start working with the vet immediately, and don't even try to feed until you have dosed her a few times with the appropriate meds.
Good luck...seeing as you have a pair, we all need you to keep them healthy!