Writing process starts with reading. Reading stories to little babies ignites imagination within them. Reading is a pre-requisite to writing well.
When my boys were at an age where they can speak but can’t write, I used to ask them to dictate a story. I’ll be their transcriber. I’ll ask questions such as why is this happening or how did this work, etc. so that the story makes sense and is complete. All these stories were bound in a folder, which is kept in our living room and whenever they want they can read it. They are amused and feel a sense of pride whenever they revisit these stories even at this age.