Jamie, Let me second Joanna's post. The mucous is a nasty side effect of the rad (I think) that starts toward the very end of treatment, gets worse for a while, then tapers off. I'm 5 months post rad and still have a little of it from time to time. It clears with a cough or two and a sip of water. Even when it was the worst, I slept sitting up and got up to spit and choke and cough every hour on the hour, or even on the half hour, for a few weeks. It's part of why we get so tired during treatment. But as Joanna says, it does end. I found that it made me vomit, so if she is just choking and gagging, she is either lucky, or it may get worse in the future. But it does go away so tell her to hang in there, there is a light at the end of the tunnel.