great-niece-in-law
1. The granddaughter-in-law of one's sibling.
2. The granddaughter of one's spouse's sibling.
2. The granddaughter of one's spouse's sibling.
My great-niece-in-law is a good person.
co-great-niece-in-law
The granddaughter-in-law of one's spouse's sibling.
My co-great-niece-in-law is a good person.