It's very hard to imagine they were otherwise exactly the same. How can you know enough about the other woman to know? Maybe her essay or interview were better.

It's very hard to imagine they were otherwise exactly the same. How can you know enough about the other woman to know? Maybe her essay or interview were better. Maybe she took harder classes or had better recommendations. Maybe she came from a more difficult background or maybe she didn't need a grant. Maybe she knew someone; maybe someone knew your sister and didn't like her. (No offense to your sister whom I don't know at all.)