Traditional families are now joined by new family models, such as families where the parents are legally separated, families with same-sex parents, single-parent families... or even couples who do not want to have children.

This book showcases different family models through the eyes of a ladybug that works for the post office and visits every house. The ladybug leaves a mysterious letter in each home, inviting the younger ones to find it. These letters bring us to the final scene, where an elderly lady who lives alone is visited by all of these families on occasion of her birthday.