A young child tells their school friends about their sister's transition.The main character, a light-skinned, overalls-clad child with curly brown hair, is questioned by their diverse classmates about where their "brother" has gone. "Was he eaten by a WHALE or SHARK?" the kids ask. "Was he taken to Mars by aliens?" The narrator responds to each line of questioning with a firm "Hey, you need to chill" before finally revealing that their sibling has transitioned and is now their sister, Lily (light-skinned and brown-haired), who's "still clever and funny and kind and cool." While the message that other people's gender transitions are really not that big a deal is an important one, the titular refrain seems unnecessarily defensive and even a bit callous given that the other children are confused rather than unaccepting. (Indeed, they don't say anything when they find out, let alone anything mean, and they smile upon seeing Lily come to pick the narrator up from school.) Because readers don't find out where Lily is until more than halfway through the story-after the kids have suggested a series of more and more outlandish scenarios-the revelation feels like a gotcha moment that inadvertently others and sensationalizes trans people. The book also features Lily's deadname several times-another misstep. The meter is uneven but readable, while the cute, scribbly illustrations are a strong point. (This book was reviewed digitally.)An attempt at a child-friendly explanation of gender transitioning that fumbles. (Picture book. 4-7)