The Metropolitan Museum's notes for this follow, "Three beautiful daughters of the Hon. Percy Wyndham, a wealthy Londoner, appear toward the lower right corner of this monumental canvas. From the left, the sisters are Madeline Adeane (1869–1941), Pamela Tennant (1871–1928), and Mary Constance, Lady Elcho (1862–1937). Rather than conducting sittings at his studio, as he usually did about 1900, Sargent painted the sisters in the drawing room of their family's residence on Belgrave Square. Seen on the dark wall above them is George F. Watts' portrait of their mother, which establishes their genealogy as well as the artist's by reminding the viewer of his ties to painters of the past. Within the bold, asymmetrical composition, Sargent enlisted fluid dynamic brushstrokes to suggest the forms and textures of the opulent white gowns, brocade sofa, and huge white peonies. The elongated figures, so typical of Sargent's style about 1900, enhance the impression of aristocratic elegance. Displayed at the Royal Academy's annual exhibition in 1900, the portrait was hailed by the critics and dubbed 'The Three Graces' by the Prince of Wales."
From From www.the-athenaeum.org; colors adjusted to approach those of other Internet images of this portrait by gogm.