siblings of Efficiency xx

half siblings maternal 2 half siblings paternal 4

half siblings maternal

broodmare Blue Violin xx (Thoroughbred, 1951, from First Fiddle xx)

Blue Violin xx
gender-female
1951

First Fiddle xx / Blue Larkspur xx

broodmare Penrose xx (Thoroughbred, 1950, from Shannon II xx)

Penrose xx
gender-female
1950

Shannon II xx / Blue Larkspur xx