The family of younger protagonists holds more weight than you might realize, so be sure to empathize on family throughout your writing if your protagonist is 18 or below. The way a young child (10 and under) and their parents interact tells the reader whether or not that child has respect from other adults. This sample interaction between a protagonist (let's call him Declan) and his mother (Pam) is an example of character development through family with a young child of 8.
Declan immediately groaned as he walked into his room. His mom was staring in the mess of clothes on his bedroom floor.
"Declan, did I or did I not tell you to put your laundry away?" Declan kept glancing at the door, waiting for the conversation to be over.
"I did put my laundry away. Just not in my drawers. Mom, could you please just let me get my game and go? Peter's waiting downstairs, and you're always telling me that I shouldn't make people wait..."
"He can wait a minute while you put away all these clothes."
"I have to go downstairs right now! We're going to be playing that new game I got for my birthday. He knows how to get past that level I'm working on." Annoyance flashed across Pam's face. She was sick of him bringing up video games all the time.
"Some video game is not more important than doing household chores."
"I've been waiting to play this all week!"
"You can wait a few minutes longer."
How have you built family members around your protagonist? Has this helped your writing? Let me know in the comments!