I've seen extra pinky holes, but never one for the index finger. There's nothing rule-wise that would prevent her from having either or both. You are allowed to have a gripping hole for each finger, and many bowlers have extras for exactly the reason you describe. Maybe the holes are too loose, and she's having to put more effort into holding the ball than she really should. In particular, an over-sized thumb hole can make you squeeze the ball considerably.
What weight does she throw? It sounds like she's a conventional-grip straight bowler, in which case there's not much to worry about core-wise by a drop in weight. If she's throwing 14# or higher, a reduction in weight might help the pain more than an additional finger hole (on the other hand, the extra hole is a couple of bucks at the most to try out, a new ball is a lot more).
SH
Edited on 9/1/2006 10:23 AM