speaking for my own experiences when I was learning to dive, I had lots of problems and questioned whether or not I would dive. Had what i called my "freak out" experience (I think I have it on one of my blogs), and figured I would never dive again. I had a driving factor, my determination. If this person the OP discussed that can’t clear her mask was encouraged to keep trying, not pushing her to try, but encouraged, she will learn. I was lucky to have instructors who told me to take my time, and then even luckier to find a dive buddy who was patient, and taught me much, without being overbearing. Remember, learning to scuba is teaching your body to do something that is not normal for it. This takes time.