Does she have any particular desires in a college yet? If so, are there any which are best evaluated by visiting?
It is possible that a given student only really cares about characteristics that are easily evaluated by means other than a visit. (e.g. “does it have the academic courses and majors that I am interested in?”, “is it within budget so that I will not have huge amounts of debt?”)
To make the most out of visits, it is best if the student has formulated a list of things to look for while visiting each school (the things to look for may differ from one school to another).