Lady Jemima Grey (1698–1731) by Charles Jervas (Wrest Park - Silsoe, Luton, Bedfordshire UK)
From bbc.co.
This portrait probably dates to around 1715 by comparison to the dresses worn by Mary Wortley Montagu and Viscountess Townshend.
Keywords: Jervas, Jemima Crew de Grey, Crew family, de Grey family, Duchess, British, straight coiffure, jeweled hat, gown, scoop décolletage, collar, long tight sleeves, kirtle, girdle, shoes, theatrical dress