Now, of course, there are ways to get around this. If the adult characters act in a way that children can identify with or understand, sometimes that will win over the editor. And if the adults happen to be adult animals, you will have a much easier time marketing the story. (Unless the editor doesn't like anthropomorphized animals.)
If your characters can't be morphed into animals, and the situation they are in is not one children are likely to encounter, your story is headed for the inactive file. (Which is in essence just a temporary resting spot on the way to the wastebasket.)
And this brings me to the story I'm posting today. I don't know how to change it, and I still have a fondness for it. Who knows why? It makes me smile, and on one more drab, cold, and sunless day I need all the smiles I can get. I hope it brings a smile to you.