Here ls a method I used with my Neuro. He always has me seated toward the window light and then does the pupil test. Well, they contract at about the same rate. Two years ago, I turned off his lights and told him to look at my pupils. The CH side does not dilate properly in low light. And it takes quite a while to return to almost normal post cycle. He was giving me a bit of a hard time and wanting to treat for migraines. That changed his mind. The other pupil was huge and the CH one was 1/2 the size of the normal one. 'Oh, you do have Horners!' Ah, yes I do. My eye does not droop because I exercised the muscles to hold it open so much one year that I now have brow wrinkles on that side only and the eyelid is more wide open than the other one! It had gotten so bad that I could not read without killing my neck looking down. So, it became a daily project. He also was running with the normal runny eye, runny nose bit. Well, now I seldom get that, but the CH side of my head sweats profusely during a hit.
Try it at home first. If you are still having CH, it should show up that way. It beats me how they just look at contraction and not expansion, but they do.
And there is the old Nitroglycerin trick. They use it sublingual for Angina. But, for a CHer, it will bring on a hit. Not a migraine, a cluster. Painful way to go, but provides proof.
She needs to rethink or catch up on her CH knowledge!!!!