The Adults Problem (I am making up my own technical term here) is a problem in writing middle grade / middle reader fiction (herafter, MG). In MG, you want your protagonist to be a kid. And you want your protagonist to face and solve his own problems.
Which means that your kid either has to have no adults around (he's an orphan, he's lost, he's at boarding school), or the adults are the badguys or the adults are neutralized in some other way (they are prisoners, they can only help sporadically, they don't know about the problem).
Below is an excerpt from my current project. The kid protagonist travels with a couple of adults, but in particular with a Troll, Grim Grumblesson. This is the Adults Problem, exacerbated; Grim is a big, powerful adult. I deal with the Adults Problem in various ways, including this snippet, in which I make Grim Grumblesson a liability.
The heroes are exiting a burning hat factory via a rooftop window.
* * *
“Come on!” he yelled to Grim.
Grim nodded, but he held his head stiff and he looked like he was chewing his lower lip with his big tusks. Something was wrong.
Grim didn’t move. He looked frightened. He didn’t look down.
He was afraid of heights.
There was noise inside the building. Grim turned and pointed his gun back inside the window and pulled the trigger.
The hammer of his gun was so big, Charlie could hear the gun misfire from forty feet away.
“Now!” Nathaniel de Minimis shouted. He spun through the air around and behind Grim Grumblesson and poked him in the backside with his spear.
Grim jumped forward. He hit the roof hard and shingles scattered beneath him as he started to slide.
Charlie saw faces at the window, but he had no attention to focus on them.
Grim Grumblesson was sliding towards the abyss, and his eyes were closed.