The War That Saved My Life and The War I Finally Won by Kimberly Brubaker Bradley

 Ada has never been outside.  She has never left their flat in London.  She waves to people outside from her chair but if her mother catches her, she will be punished.  Ada and her brother, Jamie, are evacuated from London just as England enters WWII.  They are placed in the country in the care of Susan, a woman who is grieving the loss of her friend.
Although the books are set during WWII, and the casualties of war do play a role but the books are more about the importance of family and healing physically and mentally.