Forget-Me-Not by Maxine Trottier, illustrated by Nancy Keating

From chapters.ca:
A poignant tale of how The Great War touched a country, and of how a man who was certain he had lost what was most important to him, finds it again through the friendship of a child. It is a story of honour and remembrance. One day in the summer of 1917, Bridget Keats sees something new. A stranger, Jake Wiseman, has come to their small Newfoundland outport. A mysterious soldier who will not show himself, he hides away on a nearby island in the old lighthouse keepers cottage. Some say he was a coward. Some say he was wounded and came back horribly scarred. No one knows for sure. It is Bridget Keats, who must bring his food to him each day. And it is Bridget who learns the truth of what is inside the man when a terrible storm forces Jake Wiseman to make as hard a choice as he has ever made.