Posture for left hand finger pops

Left hand finger pops should be done on the edge of the violin shoulder, I call this area the "beach."  Fingers should be round, and tapped repetitively on the tips, as this student is demonstrating.  The left wrist must be straight, as pictured.

Also, regarding her posture: notice how her nose is pointing towards her violin, lining up with the strings.  Her elbow is directly under the violin rather than behind it.  If you were to see her feet (presumably they are in play position) her elbow would probably be above her left toes.  Thus, her nose, strings, elbow, and toes line up.   Dr. Suzuki used to say this over and over: "nose, string, elbow, toes."  Make sure the "noes, string, elbow, toes" are in the same plane while Sara is doing the finger pops.  If needed, drop a pencil (eraser side down) from her left elbow, it should land near or on her left foot toes.