Did she recruit those applying for admission to the university or the graduates of it?
Most recently, Gayle spent three years at Google as a Software Engineer and was one of the company's lead interviewers. She interviewed over 120 candidates in the U.S. and abroad, and led much of the recruiting for her alma mater, the University of Pennsylvania.

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It is a little bit ambiguous, but most likely she recruited the graduates from university.

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She did recruiting FOR her alma mater - meaning she recruited new students to attend the school.
If it said AT her alma mater, it would mean she was physically at the school recruiting new employees.
If it said FROM her alma mater, it would mean she recruited graduates from the school but wasn't necessarily at the school when she recruited.