How large are the chapters? "Mid sized" can mean something different to everyone.
Did she make an effort to get to know sorority members over the past year, or was she going into rush with pretty much the same connections - only she was a year older? A woman who doesn't succeed in her first rush can't just put her goal of sorority membership on the back burner until the next fall and then try again. It's not a pumpkin spice latte
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ETA: how far into the process did she get in her first rush?
And also: if she proceeded thru rush with the outlook of "this school isn't very competitive" that could have also hurt her chances. If you're rushing it's competitive, period.