The grandchild-in-law of one's spouse's sibling.

Second cousin's grandchild.

Second cousin's great-grandchild.

1. The grandchild of one's stepsibling.
2. The stepgrandchild of one's sibling.

Sesqui-first cousin’s grandchild.

Sesqui-first cousin’s grandchild.

Child of their maternal first cousin’s child with the paternal first cousin’s child or double-first cousin’s grandchild.