My response is to prioritize your reasoning - is that the only way she can reach the goal; the only way she's learned up until now; or...the manner in which she is "consistent" - 5 out of 10 is consistent for an "experienced" 5th grader (boy or girl)? I would also begin by asking yourself if you would teach a 5th grade boy to shoot underhand? The fundamental shot is not "overhand"-strength comes from the legs, especially free throw line and out...and, kids are not old enough yet in 5th grade for gender to justify a developmental difference...and need to teach a skill in a manner that as they grow any older...a coach will never teach to shoot underhand unless they are dead-on ringer and unique like Mr. Berry. I would encourage you to teach and encourage her to shoot in a manner that she will transfer to all years ahead of her. I believe a better choice is to move her a step closer. Good luck...I know she'll thank you someday!