I know many people who went to their state flagship school and once they figured out what they wanted to major in, transferred to another school if it had a better department. Example: a friend at UW-Madison realized he wanted to do aerospace engineering and easily transferred to Ann Arbor which has a fantastic department. But I know this can be hard, esp regarding friendships.
Another thing is, does she think she’ll pursue graduate work? Because all that matters really is the last school you went to. (I have a lot of science friends!). One went to Madison for physics, which is top 20, then leapt up to MIT, then Harvard. He is now on staff at a top 10 school. Another did organic chem at Madison, then jumped to Berkeley and now has a very lucrative career in industry. I believe that within the sciences, UW-Madison, UIUC, Ann Arbor and Berkeley are like sibling schools and transitioning between any of them is quite common.