As others have said, the close contact with faculty at a LAC since they typically don’t have grad students to help thom out in the lab is going to pay dividends when it comes time to apply to a PhD program.
Since you mention premed as a possibility, there can be a downside at some schools. There are colleges that boast impressive admit numbers to med school. Unfortunately many of them get these numbers thru screening. Large publics typically don’t offer a committee letter to med school applicants but it is common at smaller schools. The way to control who applies (and hence manipulate the acceptance rate) is to screen applicants and only write favorable letters for the stronger candidates. They don’t do this under the table; they actually tell each prospect whether the letter will be favorable or not, the reason being that those with unfavorable letters know they are wasting thousands of dollars in app fees if they apply so they don’t. Voila, only strong applicants apply, and the accept numbers look great. So for the schools she is considering you should make a point of asking if the committee letter is evaluative and if so find out the criteria for a favorable letter.
On the same theme, has she looked the medical field and considered the alternatives? Its almost a reflex action among HS kids, they think of a career in medicine and its “I’m pre-med!” Doctors are far from the only ones in the health field that help people. Physical therapists, radiology techs, nurses, speech pathologists, physician assistants, to name but just a few. Hae her spend a few hours browsing on http://explorehealthcareers.org As a junior this would be the perfect time to begin volunteering in a medical setting since experience is an unwritten requirement for med school admissions and by starting now she can find out if the field is even a fit.