The Alice Network by Kate Quinn

It is 1947 and Charlie finds herself at odds with her family after her less than stellar performance at school, her little problem that will really be a problem in a few months and a family tragedy so she runs off to France in search of her cousin that hasn't been seen since the end of WWI. Her cousin Rose was part of a famous spy ring called "The Alice Network" and Charlie, along with an ex-con Irish driver and one of the Alice Network agents is off to follow her tracks and find her. What she searches for is forgiveness and what she finds is redemption and a new lease on life. I loved the way that Eve's brash character with all its flaws played against Charlie's naivety and later lust for adventure as well as Finn's charm and protectiveness.
Historical fiction of the war told in a way that we haven't seen before. Great summer escape read.