Cute enough middle grade book where the genderfluid/nonbinary rep feels very genuine what with its fluctuating and chaotic nature. The use of internet slang can be a tad much at times, it seems more reminiscent of millennial online slang rather than the generation this is geared towards. 

Also that poor dog. The guy was a jerk to get rid of her the way that he did but there are some serious quality of life issues that the dog is going to face. 

The plot gets a little bit bogged down every now and again, retreading similar ground to the point where you really feel some more editing could have been used.

Still, as a possible introduction to gender fluidity, and synesthesia too wow I rarely see that in kid's books, I think it's worth at least a quick read.