Yeah, the choice is quite strange, because Ariès focuses on the Early Modern period, above all. As far as I remember the infant Horace does not appear in the book at all. The Desmoulins' family could be an example of a new family based on emotional ties and giving central place to children (following the -contested- theory of Ariès on the "invention of the childhood" and the transformation of perception of children as radically different from adults and with radically different needs).
The book is worth reading, but it does not have much to do with the Revolution, if not in a very broad context. Sibylla