shaochieh -- If the diagram shows the track to the right of the thumb hole and to the left of the finger holes, she is a full roller.  With the layout as you show it, if the ball has a dynamic core the track is probably flaring over both the thumb and finger holes.  If the ball has a pancake core, the layout is OK, since the track will flare only slightly.  --  JohnP

shaochieh -- You need to check the Storm web site (or send their service group an e-mail) and see if the Thunder Flash has a dynamic core in the weight she uses.  If she's not rolling over the holes (thump, thump, thump, . . . ), that's a pretty good sign it has a pancake core.  I would have to know more about her skill level to advise whether a ball with a dynamic core drilled for a full roller would help her scores.  My best guess is that the money would be better spent on some good coaching.  --  JohnP