Grand Ladies

Her brief Wikipedia article is here while her article in the peerage is here. She married as achild and two times afterwards and may have published poetry under the pseudonym Ephelia.

Lady Mary Villiers, full-length, in a white silk dress standing before an open curtain, holding a rose after Sir Anthonis van Dyck (auctioned by Bonhams)

ca. 1636 Mary Villiers, Lady Herbert of Shurland by Sir Anthonis van Dyck (Timken Museum of Art - San Diego, California USA)

ca. 1636 Mary Villiers, Duchess of Richmond by Sir Anthonis van Dyck (North Carolina Museum of Art - Raleigh, North Carolina USA)

Lady Mary Villiers (1622–1685), Duchess of Lennox and Richmond by Sir Anthonis van Dyck (Tyntesfield Wraxhall, Bristol, Somerset) BBC

Mary, Duchess of Lennox and Richmond (1622–1685) with her lady’s maid, the dwarf, Anne Shepherd, with lettering and inscription lower left Mary duchess of Richmond daughter of Duke of Buckingham by Sir Anthonis van Dyck workshop (Dorotheum)

Lady Mary Villiers (1622–1685), Lady Herbert, Later Duchess of Lennox and Richmond, as Saint Agnes by Sir Anthonis van Dyck (Lacock Abbey, Fox Talbot Museum and Village - Lacock, near Chippenham, Wiltshire UK)

1640 Lady Mary Villiers, Lady Herbert by circle of Sir Anthonis van Dyck (auctioned by Christie's)

Mary, Duchess of Lennox by Wenceslas Hollar after Sir Anthonis van Dyck

Mary Villiers, Duchess of Richmond and Lennox by ? (Skokloster slott - Uppsala, Uppsala (County), Sweden)

ca. 1655 (estimate based on children) Mary, Duchess of Lennox and Richmond with her children, Esmé and Mary Stuart by John Michael Wright (auctioned by Bonhams)

Mary, Duchess of Lennox by Anthony Russell (location unknown to gogm)