This pedigree is authentic to a mare by St George*, not necessarily the one named Queen. Sanders Bruce, compiler of the American Stud Book, found part of the pedigree advertised in a newspaper which showed the Cassius cross, and he extended it to Primrose by naming Queen as the St George* mare.

However, Robin Grey's owner, Benjamin Hyronymus, stated that he had never received a certificate to clarify the pedigree of Robin Grey. Bruce said he believed his extension to be correct, based on a letter

Grandam of Robin Grey which sired several mares which bred on successfully