The earrings sold by Wooley & Wallis in July 2021 are from the same ruby parure but are NOT being worn by Helen in the photograph.
As "Baroness Jessel" (married to 2nd Baron, as her 1st husband), Helen was inside Westminster Abbey for The Queen's Coronation in 1953 and wore the rubies as a necklace, with the main Londonderry diamond tiara in her hair (just as Edith her mother had done at George VI's 1937 Coronation, and Theresa at the two coronations of George V and Edward VII).
Helen was the only Londonderry daughter who was entitled to attend the 1953 Coronation as a peeress, so wore as much of the jewellery currently on loan to the V&A (eg diamond stomacher) as her mother could pin on to her her. She also wore her mother's Marchioness coronation ermine & red velvet robe modified for lower rank of a Baroness.
Helen's younger sister Mairi could not attend the Coronation in the same way as Helen because her husband's title, of "Viscount Bury" is a courtesy title, not a peerage title as eldest son of the 9th Earl of Albemarle (who also was in the Abbey in 1953).
Finally, the Londonderry ruby parure was sold in the 1980s by Helen's third husband after her death, to SJ Phillips in Bond Street. However, the large ruby ring of the parure was not sold. (The ruby ring still belongs to the family as Edith retained that ring and passed it on to a different daughter to Helen).
The ruby parure (minus the ring) is the only portion of the Londonderry ancestral jewels which does not still belonging to the extended Londonderry family.