When their parents return to work after the birth of Charlie, Teddy, P.J. and Gabe must pitch in, getting very familiar with baby formula, burps, clothes, and babysitting while navigating typical teenage life. Their adventures continue as Charlie becomes an internet sensation, Gabe learns how to deal with a bully, PJ gets locked out of the house with Charlie inside, and Teddy gets her heart broken. The entire family even takes a vacation to the mountains! These kids have a lot more on their plate than just homework; they must take care of their baby sister while navigating teenage life.