Based on her interests, it sounds like computational biology or bioinformatics would be of interest to her. A lot of the strong programs are at ivies (Cornell, Harvard, Princeton) or the big flagships University of Washington and UCSD, but have her check out CMU (are purple states ok?) and University of Southern California and see how the net price calculations work. University of Rochester has a very math/statistics bioinformatics program - less computer science than some of the others, but has the flexibility she likes. Questbridge will obviously open a ton of options if you qualify.
Also don’t hesitate to look at schools where double majoring is easy - that’s what my daughter ended up doing to create her own computational biology program with degrees in Biology and Computer Science.