Could be that, like me, she just has poor kinesthetic sense. I never even knew what that was, until I was a sophomore in high school. The teacher in my social studies class said it was one of the things they tested for when one tried to get into the flight training in the military. Wanna do a quick check of your own?

Do not do this in front of a mirror. Just hold your arms out to the side, then touch the tips of your index fingers to each other above your head.

Did you get it right? I cannot. Eventually the index finger of one hand will bump into some part of the other hand ... but people with good kinesthetic sense - which means your body knows instinctively where all its parts are - can do it flawlessly every time!