The only one I know about firsthand is the U of Miami.
They have become quite a force in the IHSA (Intercollegiate Horse Show Asosociation) and she could get really involved with horses and competition (western, hunter seat equitation and Dressage) if she wanted to while in college there. Like, they have a big instruction staff, facilities and everything.
I won my Intermediate equitation class there, though!
I read a bit about the USC coach and she has a strong Eventing and Dressage (=good basic riding technique) background and I like the pictures of her riders posted on the website very much (they look like they know how to ride and not just sit on a horse and equitate). Also, USC lists Equestrian as an actual varsity sport, which is great for funding.
College of Charleston seems pretty into the hunter seat equitation IHSA, but no dressage. They have it as a varsity sport, too.
Pepperdine looks to also be a hunter seat equitation school, although I can find nothing about who the instructors or coaches are. It is nice in that there are varying levels of participation within the club; competing, non-competing, etc.
Hope this helps. I think she needs to decide the following:
1) How much do I want to commit to riding?
2) How much do I want to show?
3) Do I care if I am riding in huntseat equitation classes as opposed to dressage?
4) How intense do I want the overall experience to be, and how much does it matter to me to advance my skills as a rider at this time?