However, there are mtDNA identified errors in Family 5 which show that the family actually descends from three separate founder mares - see The Massey Mare entry

A third (different) haplotype appears in branches 5-d and 5-e which descend from Hag (1744). There has therefore been an error in the GSB pedigree of Hag or one (unidentified) of her descendants, the relevant horse not descending from Massey Mare

Dam of Young Hag (by Skim) through which branches 5-a, 5-b, 5-c, 5-d and 5-e of the family descend, although as stated, there are pedigree errors within 5-d and 5-e showing these are maternally unrelated to Family 5