While there are many things to love about THE LOST GIRL, my personal favorite is how Ursu captures the frustration of being a kid in an 'adult' world. There are so many times Iris and Lark try to talk to the adults in their lives (parents, teachers, etc.) and are quickly dismissed just because they are children. There were moments when I was practically shaking the book in anger because no one was taking them seriously. Young readers will find much to relate to in Iris and Lark, and I strongly recommend adults read this one too to remember what it was like at their age.
I also enjoyed how Iris and Lark have to learn to set boundaries with each other. As twins, they have done the majority of life activities together, and when that gets shaken, they have to face some problems in their relationship. It shows that no matter how much you love someone, you have to give them room to grow and make mistakes, even when you think you know what's best for them.
What Left Me Wanting More:
While I love the characters, the plot moves a bit slowly for my taste. The thread of magic throughout the novel also went from light to suddenly heavy at the very end, and I thought the build up could have been more progressive. However, I think readers who like more character-focused middle grade books won't mind either concern.
While I found the plot sometimes lacking, THE LOST GIRL is ultimately a fierce novel that explores the frustration of not being respected just because you're a kid, the importance of setting boundaries, and the power of sisterly love.