I'm trying to help her balance mental health, her grades, and a decent course load.
I'm no expert, but what I keep hearing over and over is that the 20 most selective colleges absolutely want to see that a child took the most difficult courses availible at her school. It seems to me that you are looking for something different than that - see above - which I encourage. Having time to 'be a kid' is more important that going to any particular college.
Since your child have a very strongly defined area of interest, why not explore some 'niche' colleges, such as
http://www.coa.edu/contact.htmand look on College Confidential to see what kinds of kids are being admitted to schools that are strong in marine biology?
My point is that you can't answer to 2 masters - either you want to keep the door open to one of the top 20 'name' schools and toss all other considerations to the wind, or you want what is best for your individual child(which is only occasionally the same thing - there are some kids who can do well in all those hardest High School classes, and do the ECs, and feel perfect balance - but those kids are few, and IQ isn't more than a small part of what makes a kid like that. Consider Drive and Competitive nature and Stamina and ability to see things from other people's perspective, even if the other people are adult teachers.) Think it over, decide what is best for your family, and go from there. Our advice isn't worth anything unless you make your best guess about what kind of kid you have and what is best for her.
Best wishes,
Grinity
