You mentioned Gail and Helen in a long distance relationship, and i immediately pictured Gail sending messenger pigeons, little gifts via birds, etc. And Helen responding by randomly telling the birds around her messages for Gail, and Helen feeling comforted by a few specific birds that she noticed usually kept close to her. Maybe after Gail died Helen can still sometimes recognize a few birds that like her and trust her follow her around as the Parrs move around the country