What does she hope to do with a biology degree? Does she want to be premed? Pursue grad school in the life sciences?
RIT, which has already been mentioned, was my first thought. They have a really good mix of STEMmy and artsy kids, and some majors that blend both, like Medical Illustration Another cool and highly employable major (much more interesting than the name might lead you to believe) that blends artistic ability with the life sciences is Packaging Science. (Rutgers also has a Packaging program; theirs is housed in their engineering school.)
Is she interested in minoring in art? URichmond has arts-specific scholarships that are not contingent on majoring in art, but do require a minor.
For the most part, though, I’d say that submitting a portfolio that positions art as an extracurricular, and applying to a life sciences major, is totally fine. There isn’t an expectation that people already have extensive STEM EC’s, just to apply to a science major, at the vast majority of colleges, even competitive ones.