My parents were strict about some things—swimming without adults around, being home when we said we’d be, lying, being cruel to other children—but lax on others. This was the 1980s and children—at least children in places like Coeur d’Alene—didn’t have so much structure, so much expectation. My parents let us roam outside, climbing trees and eating wild huckleberries without worry. They never seemed to have any particular expectations about what their daughters ought to be. They accepted my tomboyish nature as much as Penny’s girlieness. Title IX had come just in time, so they introduced us to every sport they could think of. They took us skiing for the first time when Penny was six and I was four, and I was immediately hooked. I don’t actually remember this, or at least I don’t think I do. I have a faint memory of looking out over the tips of my kiddie skis for the first time, of shooting out ahead of my sister on my second run so that my dad had to zoom after me, but it’s probably only that I remember being told that this was how it went. Memory is an unreliable narrator.

I will always be grateful for my happy childhood. Trust me when I tell you that no one has gone over it in more forensic detail than I have, searching for any hint of darkness. There just isn’t any.

If my destiny seemed clear from childhood, so in some ways did Penny’s. In our long hours exploring among the pines and hemlocks behind our house, Penny was always finding wounded animals: a baby bird that had fallen out of its nest, a mouse with a mangled foot. So it was no wonder—everyone would say later—that she got into medicine. She would carefully transport the animals back to our house, where my mother would help her set up a triage station in our shed, create a habitat out of a shoebox, a feeding system with an eyedropper. My mom had been raised on a farm in the south end of the state and had a handy and expansive knowledge of animals. I tagged along in these moments, a little in awe of my mom and sister.