Kongetro's comments made me really think.
According to the Royal Collection site Queen Victoria did have some Indian emeralds re-cut, and made a tiara, necklace and earrings out of them.
See the information given with the great emerald girdle of Maharaja Sher Singh https://www.rct.uk/collection/search#/24/collection/11291/emerald-girdle-of-maharaja-sher-singh
That information opens up another discussion, which is perhaps best left for another thread.
To try to solve the riddle of the origin and future disposal of the emeralds Victoria wore to the Stuart Ball on 13 June 1851 , I thought it might be helpful to list what little is known about Queen Victoria's emeralds prior to her receiving some Indian jewels from the East India Company (originating in the Lahore Treasury) on 23 October 1851.
So as not to confuse matters unnecessarily, I will not list what sound like very minor items with emeralds.
1835 for her Confirmation . Queen Victoria received what she described as a "set" of emeralds from William IV and a similarly set headpiece from Queen Adelaide.
1836 for her 17th birthday the Duchess of Gloucester, the Landgravine (Princess Elizabeth) and Princess Sophia gave Queen Victoria an emerald brooch and bandeau.
1837 for her 18th birthday Victoria recorded receiving earrings from her mother. She described them as "...earrings of gold, like serpents in shape with emerald drops..."
1840 from her aunts an emerald bracelet for her wedding. (Some of us think that is a bracelet which has been worn by Queen Mary and QEII)
1845 Victoria recorded wearing an emerald diadem designed by Albert.
1846 Winterhalter painting It is assumed that the tiara in this painting is the one made in 1845.
1850 June Queen Victoria recorded wearing an emerald and diamond diadem and parure for the christening of Prince Arthur.
The water colour above suggests that Queen Victoria was not wearing an emerald necklace, but perhaps she was wearing some of the brooches depicted in Winterhalter's 1846 painting, even though the artist does not seem to have depicted them.
1851 13 June Stuart Ball
1851 23 October gems and jewellery from the Lahore Treasury.
While it is more than likely that some of the jewels Queen Victoria wore for the Winterhalter painting of 1846 may have included the gifts from William IV, Queen Adelaide, Victoria's aunts and the Duchess of Kent, it is difficult to say with certainty. It is also possible that the gemstones were purchased to make those jewels.
I suspect that we need to look more closely at some of the emeralds now in the Gloucester collection. But, I didn't want to confuse the issue in this thread.
Like the jewels and gems from the Lahore Treasury, the jewels said to have come from the Queen of Oude did not enter Queen Victoria's collection until later.
One possibility is that, at least, some of the emerald cabochons are in the vaults. When I was looking to see if any of the ladies had worn anything like them in more modern times, I remembered this image of Queen Elizabeth the Queen Mother which has puzzled me.
We can be sure that the jewel on her handbag is an emerald because she is also wearing Queen Alexandra's Welsh emerald bracelet.
But without additional information, the origin of this cabochon emerald remains uncertain.