redpill: The question remains: How did she do it and how does it work?
She may not have done it, not really. You may have been the one to do it. Her interaction with you may have just allowed your brain to re-interpret the signals it was receiving.
Our brains are complex things...and they aren't always that accurate in interpreting what it happening inside our bodies, especially when it comes to pain. Pain perception is a personal and mysterious phenomena - we all experience pain differently and pain is something that eludes precise scientific measurement.
It is possible that you really didn't have anything at all wrong with your wrist - you may have been experiencing sympathetic pain or a psychological pain that your brain was perceiving as physical - and the mere suggestion that the pain could disappear was enough for your brain to interpret reality correctly.
Voila! Magical healing...only thing was...you did it yourself. Your brain may have been 're-set' so that it was able perceive what was really going on.