I have this Upper MG short story collection that I want to write in which the MC has a dad, sister, step-mom, and three step-siblings. Overall that's seven people under one roof. The step-mom's ex-husband is also important and the MC's dead mom is also talked about a lot.

I was in the middle of making a really cool family tree when I realized that my readers might not need a family tree.

Is there a way of knowing if a family tree is needed or not? If not what are some ways of guessing if it is needed or not.