| Who is it? | Relationship in Genealogy | Common Ancestors |
|---|---|---|
| child of your sibling | niece or nephew | your parents |
| grandchild of your sibling | grandniece or grandnephew | your parents |
| great grandchild of your sibling | great grandniece or great grandnephew | your parents |
| great great grandchild of your sibling | great great grandniece or great great grandnephew | your parents |
The "relationship in genealogy" column differs from common everyday usage. In everyday usage, the grandchild of your sibling is usually called a great niece or a great nephew. The great grandchild of your sibling is usually called a great great niece or a great great nephew. Etc. So in everyday usage, the number of "greats" does not match between grandchildren and grandnieces and grandnephews. But with the genealogical style, the number of greats does match. This is a Good Thing.