I've been meaning to read this book pretty much since it came out and never really got to it! i do this think that since then I've hyped it up a bit in my head because I really thought I'd like it.
A couple things I did love were that while I could tell it really was conscious of not getting to close to indigenous/native american culture, it was VERY close. And knowing the author is white makes that feel a little different. 
I also totally recognize that this is a children's graphic novel, but I did find the plot point of the great-uncle to be a little confusing. Like, the grandmother seems so nice but she obviously ignored the completely wrong story passed down from her children to her grandchildren about her brother???
I do love the analogy throughout comparing Aster's experience to the trans experience. I think it's a good way to present the experience to kids of this age bracket (middle grade, 9-12). And as a bookseller, I love to recommend titles like this. 
I did really enjoy it, despite the couple of problems I had, and plan on reading the rest to see how it progresses and develops!