The Marquis and Marchioness of Graham divorced in 1950 before he became Duke. 2nd edit: I had identified the ladies incorrectly!! See Mauriz's post at https://mb.boardhost.com/historyroyaljewels/msg/1574845752.html. In the first photo I posted, the Marchioness of Graham is the smaller lady seen on the right of the photo as we look at it. So far I have only a few photos of Isobel Sellar, Marchioness of Graham. Edit: The lady whose tiara I have featured below was Lady Mary Boscawen.
Original Post.
The photos below are of her as Marchioness of Graham.
At the State Opening of Parliament in November 1937
At a Coronation ball 1937
1