Everyone who has Nancy Jane Harless as their great-grandmother will share some segments of autosomal DNA with others who have Nancy as their great-grandmother. Those who are mtDNA descendants will share the same mtDNA. Those who are an X-DNA descendant may share some segments of their X-DNA with each other.
Everyone who is a 2nd cousin once removed (or closer) to another relative will have some matching autosomal DNA. If not, there is something wrong with one or both of their ancestral trees.