We start with an economic approach. We look at what are the greatest causes of death in the developing world, and what causes the largest amount of disability, which would prevent you from getting a job. A lot of those deaths start with diseases, diseases we don't get in such a great number in the United States.

I'm happy we have three healthy children and we'll stay with three healthy children.

When girls are educated and free to pursue their passions, they contribute more to a thriving society. When women have a voice, they raise it to demand a life that is greater than what they've been told they have a right to expect. And these demands change the future for everyone.

[Bill Gates] wanted me to stay working at Microsoft, but I didn't think he could be CEO and we could have the family life that we both had growing up, which is what we envisioned. I knew I would go back to work at some point later to some profession. I just didn't know what.

I went to business school, and I went straight from that to a nine-year career at Microsoft. Eventually, I ran a big chunk of the consumer products division for Microsoft.Then I left with the birth of our first daughter because Bill and I both wanted to have a few kids.

That's universal - we all want to bring every good thing to our children. But what's not universal is our ability to provide every good thing.

We set out what's going to be our work time versus our foundation time versus family time, and we'll reassess that... sometimes every week.