That's true. And then again, some people just know they don't want kids ever, you know? At the end of the ep, when they'd found the boy, it seemed like she might change her mind. I think seeing what happened to him (even tho it was ultimately a happy ending) just reinforced her desire to not have kids. She even says to Booth something along the lines of, "Why would anyone want to bring a kid into this screwed up world?" Plus, because of what happened to her parents, she might be afraid of having a child and then something happens to her, and then the child would be alone, like she was. She did, however, have compassion for Booth's feelings about finding this little boy, which I thought showed her human side a little bit.