I'd be pleasantly surprised if your Mom was eating anything after such a recent glossectomy and ND. I know it's been two months since mine and I can't swallow anything not even a sip of water. So if she cannot eat as suggested, that would be pretty normal. My advice would be to stay on top of the radiation skin burns, they creep up very quickly. Use the lotions, and push the doctors and nurses especially for advice as the focus is on curing the cancer so the "side effects" can be somewhat overlooked, You do not want your mom to end up like I did, having to go to burn dressings,
Finally, redo your mental calendar. While everyone does react differently to radiation, the worst usually comes in the weeks and month AFTER the radiation is done. If you know going in that the race is longer than it appears, it does help to finish. Last but not least, check into OCF with any questions or just to vent, No better bunch on the internet
Charm