Note: This started as a reply to a comment of an earlier post ; since one can’t easily add formatting, pictures etc. in a comment, i decided to publish it in form of a post.
Nicolas (1739-1792) and his brother Robert (1754-1854) Delaunay (sometimes also referred to as De Launay) were both active as engravers/etchers in Paris. Nicolas, pupil of Louis-Simon Lempereur (1728-1808) and later entitled to Graveur du Roi (“Royal Engraver” of Louix XV), was one of the contributors of engravings to the 1773-83 edition of J. J. Rousseau’s Oeuvre Complètes (Complete Works) after designs of Jean Michel Moreau (also called Moreau le Jeune).
One of Nicolas Delaunays most popular compositions after Jean-Honoré Fragonard (1732-1806) is Les hasards heureux de l’escarpolette (“The Happy Accidents of a Child’s Swing“). Artheque cites also La bonne mère as one of his “big” compositions.