Green’s Dictionary of Slang

a small satchel or bag worn by a woman.

1800		J. Gillray Print 12 Feb. in Cunningham Eng. Women’s Clothing in 19C (1937) 73: [cartoon caption] A number of disputes having arisen in the Beau Monde, respecting the exact situation of ladies Indispensibles (or New Invented Pockets) .
1822		N.-Y. Eve. Post 14 Dec. 2/2: About 6 o’clock last evening, a savage looking fellow, attacked [...] two ladies [...] and after knocking them down, robbed [one] of her ‘indispensible’, containing $130.