I think it’s much more likely that she got lucky. She can’t have been the first woman to try. He may have started to realize just at that time that he needed more help for some of these things.
To be fair, consider this: she was a new MBA graduate in 2009. During the summer of 2008, she had internship with Lehman Brothers, Bank of America, and 85 Broad (85 Broad is a None-profit organization founded by Women MDs/Partners at Goldman sachs). In 2008, every banks was firing people, nobody was hired. Lehman bankrupted. Yet, she got 3 jobs. And she had no real world work experience, especially in finance(before MBA, she was an undergraduate at harvard). After graduation, she got a job with Warren Buffet when I think she could be the only person in her MBA class who got a job.