Many of the debates about Down syndrome within our culture center around a similarly dualistic understanding—either people with Down syndrome are suffering, in a comprehensive way, or they are "angels." Thinking about disability in terms of what is "good" and "not good" helps me not to categorically assume that disability is a mistake or that it is merely a social construction. It helps me instead to treat each individual as an individual and to name the aspects of their physical and emotional lives that are hard, that cause separation and pain, as well as naming the aspects of their lives that are good.
At the end of your story you conclude that "Penny is neither a rebuke nor a reward. She is a child, not a product of sin or biological happenstance or of any lesson we needed to learn. No. This happened so that the glory of God might be revealed." How have you seen this revelation unfold over time?
First, people tell me that because of interacting with Penny, they have been willing to consider welcoming a child with Down syndrome into their own family. In most cases, this means women would not terminate a pregnancy due to a prenatal diagnosis of Down syndrome, but I have also heard from women who are considering adopting a child with Down syndrome in part because of getting to know Penny.
Second, I've come to understand God's character as well as our humanity in a much fuller way due to Penny's presence in my life. I used to think that an image of perfected humanity was more or less a superhero—tall, dark and handsome, with 20/20 vision and no real needs for other people. I now believe that people with disabilities offer an image of perfected humanity (which is not to say that people with disabilities are perfect!) through their more-evident need for other people. God's glory is made manifest when we love one another and care for one another, and Penny has shown me a lot about love.