The proposed relationship of Grace Humphrey as the mother of
Helen Louise Dunlap and
Majorie Dunlap is supported by DNA evidence indicating shared ancestry within the family lines.
Specifically, DNA evidence confirms a 1st cousin, once removed relationship between ST (a descendant of the Helen Louise Dunlap ancestral line) and DT (a descendant of the Majorie Dunlap ancestral line) with 356.81 cM of shared DNA across 20 HIR segments.
This match is consistent with their placement within these shared ancestral branches.