Be a top student in a less competitive high school or be an average student in an highly competitive high school, that's a tough call.
All decent high school are all competitive in their own way but being in a highly competitive school, it makes you humble, it makes you aware that you are not a big fish in a small pond, it will show you that there are many more equally talented students exist, and I believe it prepare you more for the big word.
IHS's daughter being close to top 10 of highly competitive school is nothing short of remarkable. And being able to get accepted to UC school of her choice, that's just outstanding.