It likely will allow her to steer clear of more shallow employers
Consulting firms value degrees from the most prestigious schools. This may be in part due to shallowness or snobbery of the people working their who make hiring decisions. Another factor is that firms like McKinsey charge their clients a lot of money per consultant hour, even for consultants who just graduated and have no business experience. It may be easier for corporate clients to believe they are getting their money's worth when the 20-something consultants are from a "name" school. The shallowness of clients results in shallowness of consulting firm hiring practices.
I'd rather hire a 2400 SAT student from Rutgers than a 2100 SAT student from Princeton...
It's possible that a factor in the elite college graduate preference is that many kids have to work like dogs to get into those schools and may have to work very hard to get a decent GPA at them. Consulting firms are known for the long hours they require, and many graduates of elite colleges have spent their youths being conditioned to the idea of working 70+ hour weeks. So picking people who won't question the hours could be a "rational" factor in the decision-making process. I don't know; I'm only speculating here.
As for the SAT scores, scores of 700 and 800 are separated by 3-ish wrong questions, and I'm not really sure that this is a real difference in terms of predicting how well someone will do in a job. There are way too many other factors influencing that outcome.
