I think there are some very good posts here.
The University of Rochester is generally an underrated and very good school – much stronger in terms of faculty (though I confess to knowing about social science and science but not humanities) and I would guess in terms of students than the list of very respectable LACs listed above as possible options. If my perception is correct, your daughter could end up at a school that offers less than Rochester.
Could a gap year help in admission? Maybe, but only by doing something unconventional. My son took one after graduating from HS and applied to college during the gap year. At freshman orientation, the Dean of Admissions addressed the freshman telling them what a wonderful class they’d assembled and gave anonymous cameo descriptions of several incoming freshman. The intent was to show how interesting the group was. She described my son and drew on some of the things he did during his gap year (work on a presidential campaign, co-author a young adults novel, helping a professor on research at a university, etc.). So, his activities may have helped.
My son needed the gap year as he had to do a surgery. However, he felt he was a lot more mature starting college one year later. He was more focused on learning and doing well than he might have been a year earlier.