A Far-Flung Life by M. L. Stedman

Western Australia, 1958. A truck rumbles along a lonely outback road. A moment's inattention, and in a few muddled seconds the lives of the MacBride family are shattered. Instead of leaving them to heal, fate comes back for them in a twist of consequences that will cause one of them to lose their life, and another to sacrifice theirs for the sake of an innocent child.