your great cousin twice removed.........i think
Third cousins once removed.
Second cousins, once removed.
First cousins once removed.
The grandchild of your grandmother's first cousin is your third cousin. The grandchild of your grandmother's second cousin is your fourth cousin. The grandchild of your grandmother's third cousin is your fifth cousin.
Your child and your nephew are first cousins, so your grandchild and your nephew are first cousins once removed.
Second cousins.
The grandchildren would be the parents, aunts and uncles, and first cousins once removed, of the great grandchildren.
You are great great aunt to your niece's grandchild. Your children and your niece's grandchild are first cousins, twice removed.
A person's grandchild and grand niece are 2nd cousins to each other.
Your son and your brother's grandchild are first cousins once removed.
Your grandchild and your niece are first cousins, once removed.
Your niece's child and your grandson's child (your great grandchild) are second cousins, once removed, to each other.