This. I think there are elements of fantasy of what it's like to work at a big corporate vs. working 'for' investors.

Also, I can't help thinking you'd learn a huge amount at YCombinator even if at the end of it you said, you know what, this isn't for me, you'd be doing it from a position of having actual experience that tells you that. She also mentions she'd prefer to work for a well founded early stage start up - I wonder where you can find those?