You don't say if your jacksons is wild caught or captive breed. Assuming that she is wild caught the problem could be associated with the stress of shipping/handling by the exporter/importer from country of origin. Or even parasite infestation. Also, not knowing what your level of experience is...
Lip Problems
Mouth rot can often cause the kind of swelling that's present in your chameleon. Sometimes bleeding of the gums and a cheesy appearance to the inside of the mouth on the gums as well. You can clean it up with a Q-tip and peroxide. However, I would only do this once as peroxide will...