N.B.: This post was originally written in November 2016 in response to repeated comments from one commenterl explicitly arguing that we shouldn't adopt, either implying or directly saying (I don't remember which, and I have no desire to revisit those comments) that I didn't have the temperament or ability to love an adopted child the way they should be loved.
No adopted child can replace a biological child, either lost or imagined. A new baby doesn't replace a child who died. I'd go even further - no person can replace another. Even a husband cannot replace your first love. And to take it even further, I would argue that no creature, no being can replace another. Although they may fill similar spaces in my heart, Biscuit is not a replacement for Mara. Robin did not replace Quickstep. Each of them is a unique individual, deserving of love for who they are.
Posey is not Cindy is not Mercy is not Epsy. Only 3 years separates these four girls, our assorted (more or less) nieces, but they are worlds apart in personality. Posey turned four this summer; she is energetic and exuberant and full of life and at least a little spoiled. She is used to being the center of attention and having the adults at her beck and call. She loves to swim and adores dinosaurs and Elsa with equal fervor. Cindy turned six this fall, and I often find myself wishing I could keep her. It's not that her parents don't love her, but neither one of them is as mature as one might hope. We gave her a Snow White Disney Animator's Doll for her birthday this year, which rendered her speechless. When she regained the power of speech I think the first thing she said was that Snow White was her favorite princess; her mother said that she didn't know that. I did because she had told me several times before. Cindy is quiet and sensitive and loves art. The chaos in her parents' lives has clearly affected her, which breaks my heart. Mercy is only about six months older than Cindy, but they are very nearly opposites. Mercy is far more bossy and opinionated, used to getting her own way. She loves to sing and dance and started cheerleading this year. Epsy is the oldest, turning 7 this weekend. She often seems more comfortable around adults than children and clearly enjoys having adults play with her. She has a hint of bossiness and has at times clashed with Mercy (both are clearly only children). Epsy loves the outdoors, plants, and bugs, as well as art. She has handled needing a brace and physical therapy for scoliosis with remarkable calm and aplomb.
You have to see each child for who he/she is and love them for it. Sometimes I think that is one of the hardest challenges a parent must face, putting aside their own hopes and dreams for their child(ren) to simply see them and love them for who they are.