Theresa Vane-Tempest-Stewart, Marchioness of Londonderry wears the family’s diamond tiara in a portrait taken around the time of her marriage in 1875; more on the tiara over here!

Antonia Wellesley, Duchess of Wellington wears the family’s diamond tiara for the Duke of Wellington’s Waterloo Banquet at Apsley House in London, June 2015; the tiara has been with the family since the nineteenth century

Vivien FitzGerald, Duchess of Leinster — fourth wife of the 7th Duke of Leinster — wears a tiara and necklace as she travels to the State Opening of Parliament in London, November 1975; I don’t have any additional information about the jewels