I assume there's a good relationship between the undergrad divisions and grad divisions. Georgetown is more familiar with their own undergrad than anyone else, so they know the value of grades in certain classes and the true value of an overall GPA. One of the risks that law schools take in accepting students from a wide range of schools is that they don't know the true value of the UG gpa. This is part of the reason why they rely on LSAT. By choosing from their own pool of qualified applicants, they are hedging against some of the risk inherent in varying UG experiences. Lesson? Makes sense.
In purely statistical terms, it will be very difficult. I'm assuming she's hispanic, but this does will not get her many URM points [the boost is much much more significant for blacks]. She should probably retake the LSAT and really play up her background.