In Grow Up, Tahlia Wilkins, young Tahlia is excited to redeem herself at the end of school summer party hosted by the popular kid, Noah. The year before, she’d dressed in what she now realizes was a childish outfit (wearing a rashguard and shorts) while everyone else wore fancy swimsuits. This year, she’s ready to correct her mistakes and make a statement with her best friend Lily. That is until she gets her first period. It’s more stressful because her mother is out of town leaving her with her dad and two older brothers whom she can’t stand to tell about her period. With only Lily on her side, Tahlia has to figure out how to buy pads and tampons, use a tampon, avoid toxic shock syndrome, and make it to the pool party. Unbeknownst to her, life has a couple of other changes in store for Tahlia.