18th-Century Clothing: A Woman's Pocket Was a Separate Bag
Two surviving pockets, of about 1784 and 1799, are separate bags; a museum record says such pockets were tied on under the skirts. Each layer, shift to gown.
Picture credit
"Pocket" by Unknown maker — https://commons.wikimedia.org/wiki/File:Pocket_MET_1996.2_CP4.jpg — CC0 1.0 (https://creativecommons.org/publicdomain/zero/1.0/)