My personal belief is that a diversity of backgrounds and life experiences outweigh intelligence and skill to a fair degree. It counteracts group-think, and fosters more innovation and creativity.
So don't feel guilty about how or why you got an opportunity. You came by it honestly, and whether Microsoft feels their benefit from you is due to your ability or your gender, the fact is you are benefiting them or they wouldn't give you the opportunity. Enjoy it and use the chance to improve yourself as much as possible.
In my experience, mixed-gender workplaces are a far better environment than the alternative. Last team I worked on was 40% female on the engineering side, and it was an absolute pleasure. Skills and productivity weren't disproportionately on one side or another, either.
Particularly, as a grown-up with a family, I appreciate the salutory effect that women have on subduing frat-house atmospheres. You probably find fewer women who think of themselves as rockstar ninja pirate hackers, but I'm pretty sure that's not a bad or uneconomic thing.
So don't feel guilty about how or why you got an opportunity. You came by it honestly, and whether Microsoft feels their benefit from you is due to your ability or your gender, the fact is you are benefiting them or they wouldn't give you the opportunity. Enjoy it and use the chance to improve yourself as much as possible.