I tried and couldn’t manage the claw grip. Appears to be she’s having problems holding onto the pen. Perhaps it’s a result of her medical problems.
I couldn’t do it either.
It is a very weird grip. If her thumb had been on top of her index finger, it is doable, but with the thumb underneath the index, it’s really awkward and awful. I wonder if it’s another thing she does as an exercise to keep the tremors away. If it’s a resting tremor, it goes away with more purposeful movement.