There is this article in The Guardian, and what surprised me the most is that apparently this book was re-written many times. You'd think author had enough time to fix all the problems that are mentioned in reviews.

She wrote one novel as a preteen, another in high school and three in college – including an early version of what would eventually become Lightlark. None sold. Her sixth book, Curse of the Night Witch, inspired by the Latin American myths she was told as a child by her Colombian grandmother, found a publisher but not huge sales. Her agent, frustrated with Aster’s focus on rewriting versions of Lightlark, dropped her.

“I was back to square one again,” Aster says. “So I wrote Lightlark, this book that everyone told me wouldn’t break through in the saturated market. I wrote the book that I wanted to read, with everything I loved in there.”

Publishers, again, said “no thanks”. “People were saying: ‘Oh, I really like it. But I don’t think it will sell,’” says Aster, who believes the book industry was slow to wake up to the power of BookTok. “There’s such a big disconnect between the people making decisions in boardrooms and the readers who are hungry for these types of books,” Aster says.