Vanessa Bell was Virginia Woolf's real-life older sister, and she appears in a fictionalized form in The Hours. Intriguingly, rather than emphasize her historical talents as a painter, graphic artist, and designer (not to mention her surprisingly modern approaches to marriage and sexuality), Michael Cunningham chooses to represent Vanessa as a paragon of domestic skill.
Unlike Cunningham's fictionalized Virginia, Vanessa seems to know exactly how to deal with moody servants and moody family members alike. Virginia thinks of her sister as using "seemingly effortless gestures" (10.17) to manage her life and everything in it, and she admires her for being able to do it all so well. In fact, Virginia thinks of Vanessa's domestic skills as "arts" in and of themselves (10.17).
By emphasizing the artisticnature of Vanessa's domesticity in this way, The Hours echoes and ramps up the very idea that inspired Mrs. Dalloway—or at least the idea that inspired Mrs. Dalloway as Cunningham sees it. As Cunningham's narrator, speaking from Virginia's own perspective, puts it:
There is true art in it, this command of tea and dinner tables; this animating correctness. Men may congratulate themselves for writing truly and passionately about the movements of nations; they may consider war and the search for God to be great literature's only subjects; but if men's standing in the world could be toppled by an ill-advised choice of hat, English literature would be dramatically changed. (7.8)
By representing Vanessa as Virginia's best and brightest example of domestic "artistry," The Hours suggests that Vanessa was one of the real-life inspirations for Woolf's own Mrs. Dalloway. She also seems to have been an inspiration for Cunningham's Clarissa Vaughan. If you want more proof, read up on the house that the real-life Vanessa shared with the artist Duncan Grant and the writer David Garnett, and compare that living arrangement to the one that Cunningham's Clarissa once shared with Louis Waters and Richard Brown.