I haven't read the book, but I think there is a big difference between a flawed character and a flawed message.

Like: Is it just that the flawed character is saying that other girls are shallow and leeches onto popular boys without having anything to offer, or is the book/story/author agreeing and implying it with how the other female characters act when not observed through that character or by never having that flawed presumption challenged?

A character having internalised misogyny and mood swings can be them clearly being torn between their fear of abandonment and their love or attraction because they are a flawed character written very well, or it can be lazy writing with no clear character understanding or reason for their erratic changes, depending on how its done.

Some of my favourite pieces of media is with characters I would absolutely hate in real life, or who are deeply flawed but understandable and/or not rewarded for it.

I really liked the book, I had read Warrior Girl Unearthed first though and got to know Daunis as an adult in that story before going back in time to see her as a teen in the first book. I liked her in both books but understood her more after reading Firekeepers Daughter. You should check out Legendary Frybread Drive-In if you like this book!