The Story of My Life Ongoing, by C. S. Cobb

It's not easy "choosing not to choose," especially for a nonbinary teen in 2007.

Corey was born intersex, but their father and stepmother didn't make a big deal about it. Then Corey's dad dies suddenly. Now Corey's disapproving mother wants Corey to "pick a side". Corey's old enough to say no to medical intervention-but not old enough to avoid being held in a youth psych ward when their mom makes an issue of Corey's refusal to conform to the gender binary.

In the psych ward, Corey makes friends with Kim, a teen girl diagnosed as anorexic-or is she? As they work to unravel their pasts, they discover that Kim's situation is even more dangerous than either of them had ever imagined.