I have the feeling that this is something entirely different as the artist has not used artistic licence in depicting HM's other jewels. If this is the Girls of Great Britain and Ireland tiara then a lot of artistic licence has been employed.
The tiara depicted in the 1911 portrait does not have all the elements of the Girls of Great Britain and Ireland tiara and, even allowing for the fact that the tiara can be worn in different configurations, the details seem different.
Apart from anything else, the tiara depicted in the 1911 painting does not have pear shaped pearls of nearly equal size - which the Girls of Great Britain and Ireland does. The pear shaped pearls in the 1911 portrait are of very different sizes.
--Previous Message-- : : Beth - I'm so glad you gave the link. : : I think that is the Girls of Great Britain : and Ireland when it held large upright : pearls on top, and without the lower band. : : :