This was quite lovely. 
 I went into it already knowing what happens because I'm the worst at not reading spoilers. Yet, I was still pleased by the whole thing. It is about a girl (who isn't white! Yay for diversity in books!) who has been sheltered for her whole life because she is deemed ill, basically allergic to the world. The book documents her life for a short period of time in which she confronts her illness, falls in love, and learns about life. The whole thing is exquisitely sweet. 
 I think my favorite aspect to this book was the overall concept of identity, especially within the dialogue of "illness" books. Sometimes I feel YA illness books often instill a belief that physical ailments are a way to a solidified identity. This includes mental health issues. Exploring your identity may bring about some of these issues, and they can certainly contribute to one's identity, but people are way more complex than that. Sometimes books show these issues too black and white. I think this story did it in a smart way because it illustrated that we are growing and changing. Identity is a malleable thing, instead of as rigid. This book confronts this topic in a very "coming of age" manner. 
 This was a pleasant read, I'd recommend it. Plus the cover is soooo pretty ;)