I'm going to answer this question only as it relates to writer's block. There is only one answer. The members of the audience when writing fiction are the characters in your story. They are listening to you and you are listening to them, and writing what is true to their thoughts, feelings, and voices. It's a dialogue between the creator and the created, as the work develops. Once you are deep into the creative process, this is not the time to worry about what your editor, friends, family, and critics will think. Your creative allegiance is to the truth of the story, only. A sure way to suffer writer's block is to consider the opinions of critics while you write.
Of course, if you write for children, you have to understand the various genres as they relate to your reading or listening audience. A picture book and a middle grade and a YA are very different, and these differences relate to the developmental needs of their readers. But I believe that you should know and understand these differences even before you begin writing, based on your own reading experience and thoughtful study. Once the work begins, you are communing with your characters. (See my Home page for the essay Child Development and Children's Books.)
I am now working on the line edits of my new middle grade novel THE FIVE LIVES OF OUR CAT ZOOK. It is the end of a long, intense but joyous process. I'm listening hard to the voices and needs of Oona and Freddy. At this stage it's so much easier to hear them! And as I tell their story, they let me know if I'm telling it right.