<p>Outfit of the pre-teen daughter of a French "bourgeois" from <i>Galerie des Modes</i>, 1778 (Plate 45, detail): a green dress with large panniers, and a white striped pseudo-apron thing over it.  By modern standards, it seems quite impractical for a child of that age -- and the clothes of an actual aristocrat young girl of the same age might possibly have been even more extreme. (Compare the adult aristocratic dress at <a href="//commons.wikimedia.org/wiki/File:1778-jeune-dame-de-qualite-en-grande-robe.jpg" title="File:1778-jeune-dame-de-qualite-en-grande-robe.jpg">Image:1778-jeune-dame-de-qualite-en-grande-robe.jpg</a>.)  This was about a decade before the idea of sparing children most of the indignities of adult fashions took hold (compare the attire of <a href="//commons.wikimedia.org/wiki/File:Marie_Antoinette-children-1785-6-Wertmuller.jpg" title="File:Marie Antoinette-children-1785-6-Wertmuller.jpg">Image:Marie Antoinette-children-1785-6-Wertmuller.jpg</a> in 1785-1786, <a href="//commons.wikimedia.org/wiki/File:Battledore_-_Youthful_Sports.png" title="File:Battledore - Youthful Sports.png">Image:Battledore - Youthful Sports.png</a> in 1804, <a href="//commons.wikimedia.org/wiki/File:Passer-payez-Boilly-ca1803.jpg" title="File:Passer-payez-Boilly-ca1803.jpg">Image:Passer-payez-Boilly-ca1803.jpg</a> in ca. 1803, <a href="//commons.wikimedia.org/wiki/File:Philipp_Otto_Runge_003.jpg" title="File:Philipp Otto Runge 003.jpg">Image:Philipp Otto Runge 003.jpg</a> in 1805-1806, <a href="//commons.wikimedia.org/wiki/File:Jean-Baptiste_Wicar_001.jpg" class="mw-redirect" title="File:Jean-Baptiste Wicar 001.jpg">Image:Jean-Baptiste Wicar 001.jpg</a> in 1809, or <a href="//commons.wikimedia.org/wiki/File:Children-dancing-ca-1820.jpg" title="File:Children-dancing-ca-1820.jpg">Image:Children-dancing-ca-1820.jpg</a> ca. 1820...).
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Also, compare <a href="https://en.wikipedia.org/wiki/Image:Watteau_the_dance.jpg" class="extiw" title="en:Image:Watteau the dance.jpg">en:Image:Watteau the dance.jpg</a> / <a href="//commons.wikimedia.org/wiki/File:Antoine_Watteau_013.jpg" title="File:Antoine Watteau 013.jpg">Image:Antoine Watteau 013.jpg</a> or <a href="//commons.wikimedia.org/wiki/File:Dansande_barn,_m%C3%A5lning_av_Lorens_Pasch_dy.jpg" title="File:Dansande barn, målning av Lorens Pasch dy.jpg">Image:Dansande barn, målning av Lorens Pasch dy.jpg</a> or <a href="//commons.wikimedia.org/wiki/File:William_Hogarth_047.jpg" title="File:William Hogarth 047.jpg">Image:William_Hogarth_047.jpg</a> to see how little things changed from 1718 to 1742 to 1778...
18th century artists, possibly the same who did <a href="//commons.wikimedia.org/wiki/File:1778-jeune-dame-de-qualite-en-grande-robe.jpg" title="File:1778-jeune-dame-de-qualite-en-grande-robe.jpg">File:1778-jeune-dame-de-qualite-en-grande-robe.jpg</a>
1778
<i>Galerie des Modes</i>