Our Siblings' Side of the Family Story

 

One problem with using DNA for family history research is that we find silver bullet strategies often come crashing down. We put so much hope into such tests, but it turns out that DNA match lists may not contain the magic potion we've assumed would bring down those impenetrable ancestral brick walls.

There is a way around such disappointments, as I've found. It's in using DNA testing in combination with a lot of hard research work and testing strategies that can produce more useful results. One key is to test siblings. Where one sibling's DNA results may match the target test subject on certain chromosome segments, the other sibling may yield far different results, yielding another side of the family story. Perhaps this is the cause behind the red-headed step-child accusation, where one of several siblings doesn't seem to have the same appearance as the rest of the family, and yet is, indeed, a child of the same parents. Sometimes a hidden characteristic from a grandparent makes itself known in only one grandchild—and that can be the family quirk that leads us to a hidden ancestral story.

In my husband's case—as he is the proxy for my father-in-law's genetic profile—he has two sisters who were willing to test their DNA to help me with a class project I had, years ago, for a workshop taught by Blaine Bettinger at a genealogy conference. I'll call them Sister #1 and Sister #2. As I worked through the genetic differences that could be spotted between the three siblings, it was clear that Sister #2 had matches not shared by the other two subjects. Her matches, some of them quite distant relationships, all descended from her family's ancestors from County Tipperary in Ireland. I was able to confirm connections as distant as fifth cousin from specific matches which she did not share with her two siblings.

On the other hand, Sister #1 had matches from the more southern counties in Ireland. At the time when I had first realized this, I was working on connecting DNA matches from Sister #2 to the family's Tully and Flannery roots in County Tipperary and, while overjoyed to have discovered such a handy connection there, I gave little thought to the value of the other sister's DNA connections.

Now, as it turns out, Sister #1 may have the key to unlock at least some of the doors leading to Flanagan and Malloy answers from County Limerick. Because both siblings had tested at Family Tree DNA, rather than at the more popular Ancestry.com, this will mean working with a smaller universe of results, but it will also mean working with a company which, over the years, has focused on marketing directly to Irish residents at annual genetic genealogy conferences of the prior decade.

Hopefully, at least some of those many Irish DNA-testing subjects will have a useful match with Sister #1. The most likely approach will be to seek matches who are not "in common with" my husband's results at Family Tree DNA. However, I already did spot one Flanagan match from my husband's own results who leads back to a possible relative of Anna Flanagan.

Back at Ancestry.com, their ThruLines results show only seven matches connected to Anna Flanagan. All of those, unfortunately, are close cousins whom we already know. No secrets unlocked there. And though I had already prompted the system to find a father, simply labeled by his surname "Flanagan," the ThruLines system hasn't yet uncovered any more distant cousins, despite my father-in-law's tree including Flanagan descendant Johanna Flanagan Lee and her descendants down to the level of third great-grandchildren.

In addition, there are test results at MyHeritage and 23andMe, though these are only for my husband's results, not his siblings, so there is no way to compare or contrast those results, only to find matches with the rather common surname Flanagan.

Still, having DNA test results does provide one additional way to chip away at that Flanagan brick wall story back in County Limerick. Now that we're finally at the beginning of August—the official start of researching Anna Flanagan, number eight of my Twelve Most Wanted for 2026—perhaps these updated DNA matches, especially from Sister #1, will provide some answers about Anna Flanagan's roots in County Limerick.