Betti on the High Wire - Lisa Railsback

Ten-year-old Babo has grown up on an abandoned circus camp in a war-torn country, believing her circus-star parents will come back any day now. So she's none too happy when an American couple adopts her, calls her Betti, and takes her away from her fellow parentless friends, to a very confusing America. Betti misses her old home, and she's worried her real parents will never be able to find her. She's determined to run away, but as she gets to know her new parents, little sister, and even a new friend, Betti starts to feel like maybe she could be happy in her new American home.