Spouse's nibling's wife.
My niece-by-marriage-in-law is a good person.
by NSBC968755 February 25, 2023
Get the niece-by-marriage-in-lawmug. 
Get the step-co-niece-in-lawmug. The daughter-in-law of one's spouse's sibling.
My co-niece-in-law is a good person.
by Elivaldeq November 24, 2019
Get the co-niece-in-lawmug. half-niece-in-law.
by Simaduria July 27, 2024
Get the half-niece-in-lawmug. 
Get the co-niece-in-lawmug.