I usually love the Little People, Big Dreams books, but I have several reservations about this one. Several difficult topics are covered here, and while I know children are completely capable of understanding and dealing with death and the reprehensible treatment of LGBTIAQ folks in history, this text leaves some pretty big questions lying there, and a lot of kids will pick them up. Christopher does "suddenly" and with no explanation. A sentence about how he'd had tuberculosis (or even just "an illness") for years before succumbing would help stave off some kids' questions and fears. The mention of "a bizarre" treatment" that Turing is subjected to leaves about a hundred questions unanswered.
Overall, a lovely little book about an important figure, but do some research Before reading it to a child because they will have questions.