That’s great. Also, if you want to have a better idea of your child’s chances, you should be able to find out who from the school obtained admission in past years to the boarding schools in which you are interested. If your child has very similar qualifications, she should have a pretty good chance.
At the K-8 school for gifted kids with which I am most familiar, the kids who combined top scholastic performance with leadership had excellent success (three Andover matriculants, for example, plus two Choates and one Exeter in the past five years), while students who were more in the middle of their group of gifted classmates and lacked leadership experience had less success. In the case of the latter, however, I believe their boarding school “nets” were way too small. Instead of simply applying to one or two tippy tops and earning acceptances to none, they should have applied to more schools (assuming they really wanted to attend boarding school for high school).