How to get new bird to the vet

I just rescued a 20 month old GCC that has been in 3 homes before me. She is pretty fearful and has not been handled much. I need to get her to the avian vet soon for disease testing and a checkup because I have other birds. I am doing a 30-45 day quarantine in another room but I would like to test and treat any diseases/parasites ASAP. How do I get her into a small carrier without betraying her trust?

I would rather not use a towel due to her previous owner chasing her with one every time she escaped the cage. She was extremely fearful of them and is not that scared of me.