My daughter is at UR and is a semi-STEM type of person (health, behavior, and society + microbiology). She wants to work in public health, but she tends to take social-science perspective rather than a hard-core math-and-science approach to what she wants to do. While many of her friends are pre-med and engineering majors, she also has friends majoring in psychology, English, and other non-STEM fields. I don’t get the impression that there is any segregation of students by major or interests. If your daughter goes to UR, she will be in a dorm with STEM freshmen, non-STEM freshmen, and undecided freshmen, which really does encourage intermingling. And my daughter’s extracurricular activities include both STEM and non-STEM students, as well. (Lots of kids, for instance, are involved in music, dance, sports, etc. where major is irrelevant.)
Based on her experience, I’d also say that both the STEM and non-STEM professors share a common passion for what they are teaching. In fact, I think that favorite professor so far is a woman who teaches religious studies. 
That being said, UR is very research oriented, which I know can be frustrating for students who don’t have that interest. A recent op-ed in the UR newspaper spoke to the issue in a very honest and interesting way. http://www.campustimes.org/2015/11/19/knowing-what-i-know-now/