I'm going to write a little more about hunting for your story (something that happens to somebody and its significance) with setting, because I recently finished reading a book that illustrates my point. Speaking From Among the Bones by Alan Bradley is the most recent of the Flavia de Luce books. They're written for the adult market, but their protagonist, Flavia, is eleven years old, making them appropriate material for Original Content.
These books are very, very dependent upon their historical setting. As I wrote after reading the first one:
"Setting this book in 1950 was a stroke of genius. Flavia is a bit
over-the-top. Oh, hell, she's a lot of over-the-top, which is what makes
her so marvelous. But no one could begin to believe she could exist in
the twenty-first century. Her extensive knowledge of...all kinds of
things...could only be acquired in a world without TV, malls, dance
lessons, sports, and, it would seem, traditional schooling. (School is
never mentioned.) And, for me, a big stumbling block with child
mysteries is the fact that kids can't get around places on their own.
But Flavia's always jumping on her old bike and pedaling off all over
the place. It's believable in a pre-suburban world. I have
ridden my bike to the library and even a church tag sale, but it's a
huge undertaking, taking a big chunk out of my day. Traffic being what
it is, I'm taking my life in my hands every time I do it. But in
Flavia's world, it works."
Readers accept this quite unbelievable child because her stories are set in the past, and we believe things were different in days of old. We're more willing to accept Flavia's apparently self-taught brilliance because we can accept that children in the past may well have worked harder on their own and achieved more that way. If these books were set in the here and now, Flavia wouldn't work. Her wandering all over town on her own wouldn't work in the twentieth century, either, because in our culture we would fear for unsupervised children. But the past, we think, was safer--even though in every book Flavia is nearly killed. We Americans also have this image of England, especially England in the past, as being a small place with villages close together. We believe a child could bike from one village to another. Could she bike from one suburban town to another in 2013? Not where I live.
Placing those books in 1950's England has a big, big impact on the story and what can happen in the story.
Think, also, of eleven/twelve-year-old characters in fantasies. They do ridiculously unbelievable things--lead others in battle...defeat gods...escape from repressive governments. But the fantasy settings are ridiculously unbelievable to begin with. Once that setting is established, the writers can make things happen that they couldn't make happen in a real-world setting.
Related to setting is place. Check out The Five Pillars of Place at Ploughshares.
So, the point here is work on your setting to help you determine what is going to happen to whom and its significance.