If she has good speed, stick with it. my DD is now 12 and she started slapping at about 8 and it was a struggle at first. We did teach her the fundamentals of the full swing before we got into slapping and still work on everything from the full swing, power slap, soft slap and drag bunts every time we hit. My theory was always and still is, nobody cares what your OBP or batting average is at 10U or 12U or if you are the best 10U or 12U player, just keep improving and she has. If she has good speed, keep at it. My experience has been it is still very effective and she is 12 playing 14U A ball. Speed puts pressure on a defense and she probably reaches base 20% of the time because the defense makes a mistake because they know they do not have much time.