The maternal relationship between Grace Humphrey and her daughter Helen Louise Dunlap is confirmed by the direct inheritance path of autosomal DNA down to their DNA tested descendant ST.

The segmental (via DNA segment triangulation) and total DNA shared between ST and other confirmed descendants of GH/Mary Luna Bowles is consistent with the expected ranges for their respective relationships. Since ST descends from GH/Mary Luna Bowles through Grace Humphrey and her daughter Helen Louise Dunlap, the presence of significant shared DNA between ST and other known descendants of GH/Mary Luna Bowles validates the generational links along this maternal line.

This supports the conclusion that DNA was passed from MRCA couple GH/Mary Luna Bowles through Grace Humphrey to Helen Louise Dunlap, and ultimately to ST, confirming this direct ancestral connection through multiple generations.