A Wrinkle in Time by Madeleine L'Engle should definitely be on this list. (And other books written by her, especially featuring the same characters.)

All three of the main characters are heavily neurodivergent coded, each in slightly different ways. Charles Wallace is a prodigy and semi-magical 5-6 year old who didn't speak until age 4 and then spoke in full sentences, who struggles to connect with his peers and has incredible abilities which are hindered by his hubris. Some people think he's stupid when really he's anything but, because they don't know what to do with him.

Meg is a lost feeling 12-14 year old, also very smart, but only selectively in subjects she's interested in and only if she can learn in her own way. She is angry and expresses her emotions in ways that aren't always socially acceptable. She tries to fit in but she's unable to, as her mother says "You're much too straightforward to pretend to be what you aren't." She is described as being "not quite one thing or the other, not fish nor fowl nor good red herring", struggling with not being unusual in the way Charles is but not quite "normal" either.

Then they meet Calvin, who appears at first glance to be nothing like Meg and Charles, he's popular, good in school, and plays sports. But when they actually tall to him they come to realize that he has some of the same abilities and characteristics as Charles, but he's especially good at communication and is able to keep that part of himself hidden, all the while being profoundly lonely because there's no one he can really talk to as himself. He finds a home with the Murry family, which was always the element of the book that was most moving to me. Meg and Charles Wallace are 100% loved by their parents exactly as they are, and Calvin is taken in with the same sort of love.