Michael Phillips 
Heathersleigh Homecoming (The Secrets of Heathersleigh Hall Book #3) 

As the Great War escalates, Amanda Rutherford is betrayed by those she trusted most and forced to flee to protect the war secrets in her possession. Meanwhile, her family in Devonshire learns they must commit a son as well as a father to the conflict. And in a remote alpine chalet, a few weary souls find refuge from physical danger–but not the turmoil within.