Almost everyone getting concurrent chemo/rad ends up having their worse time the few weeks POST treatment. That's very very normal. Doesn't mean it's pleasant but don't think something is unusual. The thick mucous is the last stage before she will encounter what we call "dry mouth". It can last for several weeks. Remember each of us can be different. Some use soda water, some have it so bad they need to rent a suction machine. I walked around with a styrofoam cup in my pocket and spit in it all the time. At night I would wake up w/ a mouth full and barely would make it to the b/r sink. Sometimes it triggered a gag reflex and I would vomit. This will pass but then she needs to be prepared for the dry mouth.