Orphan monster spy series

"Germany, 1939. After her mother is shot at a checkpoint, fifteen-year-old Sarah, finds herself on the run from a government that wants to see her, along with every other Jew, dead. Then she meets a mysterious man who needs Sarah to pull off a spy mission he can't attempt on his own: infiltrate a boarding school attended by the daughters of Nazi top brass, befriend the girl whose father is a high-ranking scientist, and find the blueprints to a bomb...