The Republic of Birds - Jessica Miller

Olga loves the stories of the old cartographers and pores over their ancient books and maps, trying to unlock their secrets. Sometimes, she thinks she can even see into them - as if by magic. But magic is banned in Tsaretsvo, ever since the war with the birds that divided the kingdom, and the powerful magic-wielding Iagas have long been banished. Now, any young girl who shows signs of being an Iaga is whisked away to a life, so the story goes, of unspeakable punishment. When the bird army kidnaps Olga's sister in a surprise attack on the human kingdom, Olga has to venture into the Republic of Birds to bring her back. But first, she must learn to unlock her magical ability.