When Johanna was 5 months old, I met Joe, a 12-year-old with Down syndrome. Our pediatrician had given me his mother's phone number, and when she invited us over I was terrified. But Joe turned out to be a soft-spoken sixth-grader in a button-down shirt and khaki shorts who was on the lacrosse team and played the drums. While his older brother stayed outside to play basketball, Joe came inside with his younger sister to see Johanna. I was struck by the gentle way he played with her, how he stroked her hands and sang to her. I'd never seen a boy his age display such tenderness to another child, and when I mentioned this to his mom, she shrugged. "That's just Joe's nature."
When I left their house, I felt hopeful for the first time since Johanna's birth. I knew two things: This was a disability that my husband and I could live with, and I wanted us to have at least two more children. I had seen Joe with his brother and sister, how they laughed as they played Frisbee and scuffled over the TV remote. There was no question in my mind that having siblings had helped foster Joe's development. Three months later, I was pregnant.