Hi AndreaEve,
Traditionally there is not swelling from radiation treatments. It is quite the opposite.
It seems as though your doctors are taking the approach of radiating to kill as many of the cancer cells as they can before making their next move. With that stage of cancer it is a common choice of some doctors.
Nutrition is going to be very important for her during the radiation treatment. I can not stress this enough. Make sure she gets at least 2000 calories a day. You might even think about seeking the advise of a nutritionist. You doctors can help in this matter.
Good luck and keep us informed.
Jim