How To Add A Half Sibling To Your Ancestry Tree

A half-sibling relationship cannot be added to an Ancestry tree without first creating their common parent. Sometimes you have the details of the siblings but don’t know anything about their parents.

You may also encounter scenarios where two siblings have been incorrectly assigned both parents in your Ancestry tree – and you want to fix this.

We’ll cover all scenarios in this article.

How To Add A Half Sibling In An Ancestry Tree

The easiest scenario is when the person has no parents yet in the tree. You need one parent before you can create a half-sibling relationship. Follow these steps.

  1. Add the parent in common.
  2. Add a brother or sister to the existing child entry.

At this point, you may choose to add a spouse to the parent entry. By default, Ancestry will set the spouse as being a parent to both siblings. This represents them as full siblings, which is not what you want.

You’ll find options at the bottom of the screen to deselect the parental relationship for one or both children.

In the example below, both Anne and John were ticked yes when I opened the edit screen of the new spouse. I have deselected Anne as a child relationship.

How To Add Half Siblings To Someone With Two Parents

When you add a brother or sister to a person in your Ancestry tree with two parents, Ancestry defaults to a full relationship. In other words, the new sibling is entered as a child of both parents.

You will need to edit the relationship of the new sibling and remove the link to one parent.

Let’s take an example of giving John Smith a half-sister on his maternal side. The “Add Sister” dialog box will default to two shared parents – you can’t change that here.

This is what you end up with, and it does not represent the genetic structure:

So, the next step is to remove this paternal relationship. In our example, we will remove it from Anne.

In order to change relationsihps, you open the person’s profile page (click on the person and choose “Profile”). The Edit drop-down menu at the top right of the page has an “Edit Relationships” item.

In our scenario, we are removing the father from this person. This action doesn’t delete the father from your tree. It deletes the incorrect relationship of father-daughter.

At this point, if you return to view John in the tree – you’ll see this:

But if you stay on the “Edit Relationship” screen, you can also add a new person as the father. This new parent will not be assigned as father to Mary’s half-sibling, John.

The tree view would look like this:

How To Change A Relationship From Full To Half Sibling

We’ve actually covered this halfway through the previous scenario.

You have a situation where someone has two parental relationships and you need to remove one of them. Pull up the “Edit Relationship” screen and remove the unwanted relationship.

What If You Don’t Know The Common Parent?

Adding half-sibling relationships is a little inflexible with There has to be a parent already in the tree. But you may not know any details about the parent.

Unfortunately, you have to create a place-holder parent before you can add the half-sibling relationship.

When the common parent is paternal, I tend to leave the default surname to match the first half-sibling I entered. That’s just laziness on my part, as the last name is pre-populated by Ancestry when you add a father.  I should probably treat the placeholder fathers and mothers the same: set the last name to “Unknown”.

If you’ve inferred the relationship from DNA evidence, you may not even know if the common parent is maternal or paternal. What do you do in this situation?

Well, you’ve got to choose either “add father” or “add mother”. But it doesn’t matter which you go with. You can use the option buttons on the Basic Edit Page to set the gender to “Unknown” if you wish.

If your tree is public, it’s a good idea to add a comment to the placeholder profile. You could give other Ancestry users a clue as to why you’re confident about the half-sibling relationship without knowing the details of the parent.

Other Relationships

If you’re trying to add other less “common” relationships, you may be clicking around the Ancestry tree profile – wondering how to achieve what you want. We have a few other articles that may help.

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Margaret created a family tree on a genealogy website in 2012. She purchased her first DNA kit in 2017. She created this website to share insights and how-to guides on DNA, genealogy, and family research.

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