White Stockings, about 1860 GB, might be halfbred?

[cissiny]

I'm going through some old French books with stallions of different breeds, just saw something that I really want to research... The stallion Shamrock (born 1870 by Shepherd F Knaff) has always been described as a Standardbred born in the US. My book Stud-Book Vendeen (1889) had some more details though... It said that Shamrock was actually born in Great Britain in 1870, by the American Standardbred out of a mare that was "almost pure thoroughbred" (jument anglaise pres du sang)? Or even a pure TB? The name I have (from other sources, that say that Shamrock was born in the US) is White Stockings.

Has anyone found a filly, born in Great Britain about 1860 or so, named White Stockings? Of course, it could be that she is not a pure TB, but I wanted to ask anyway?

Thanks in advance,
Cissi in Sweden