One writing rule often quoted is to write about what you know. Whilst I don’t think this has to be strictly adhered too - providing you research your subject properly I think you can write about most things - but it’s a good starting point. It can be especially useful when writing a children’s story, because you’ve been a child.
(Me as a child, with my two brothers)
Of course, the world has changed since our childhood. Children now live in a world of technology, they dress, speak and play differently to how we did. But I don’t think their feelings and fears have changed that much, and that’s what I’m suggesting you tap into. Most of us can remember how frustrating it feels to be smaller than everyone else, to not be able to reach the door handle or get our toys off the top shelf. We know how scary the first day at school is, the first date, the first kiss. We know how it feels to be bullied, left out, not fit in because most of us experienced this as a child.
So before you start to write a children’s story, cast your mind back to how it feels to be a child. A good way to do this is to sit quietly, with a notebook and pen, and think of a vivid memory from your childhood. It could be when a baby brother or sister was born, losing your favourite toy, your first day at school, an argument with your best friend, the crush you had on a lad in your class. Whatever memory you choose think about how you felt back then. Then freewrite the memory from the point of view of you, the child. This should help you find your ‘inner child’ voice and help you write your story from the child’s point of view. But when writing your story, do remember to use a modern setting and write in the language children use today.