Fan Casting Alone Among Families in Sort by Tropes

An orphan, an infertile woman (or man), or any other character missing a family has the isolation emphasized by being surrounded by families. This can be a place with many happy families, even solely occupied by such people in defiance of statistics, or the character's being sharp to notice such things. The family arrangements will naturally parallel those the character feels lacking in: a Lonely Rich Kid sees parents fussing over their only child, a sibling-less orphan sees parents with their children, an only child sees sibling groups, an infertile woman sees parents with newborns, etc.