The proposed relationship of Winifred Flannery as the mother of RR and Arnold Roberts is supported by DNA evidence indicating shared ancestry within the family lines.

Specifically, DNA evidence confirms a distant cousin relationship between JR (a descendant of the RR ancestral line) and DG (a descendant of the Arnold Roberts ancestral line) with a shared segment of 320.01 cM across 16 HIR segments.

This match is consistent with their placement within these shared ancestral branches.