This is The Contemplative Charmer, kindly sent to me by Ruth Marler, who found it on the website of the Geffrye Museum in London (where, though a Londoner, I've never been). Full details say:
Mezzotint on laid paper, 'The Contemplative Charmer', extensively hand-coloured with watercolour and gouache, published by R. Sayer and J. Bennett in London in 1780.
Very tiny book she's been reading! I wonder what it was that caused her to contemplate.
