The granddaughter-in-law of one's spouse's sibling.
My co-grandniece-in-law is a good person.
by Elivaldeq November 24, 2019
Get the co-grandniece-in-lawmug. 
Get the co-grandniece-in-lawmug. 
Get the half-great-great-grandniecemug. Sibling's great-great-granddaughter.
My great-great-grandniece is a good girl.
by Hgcloziw November 23, 2019
Get the great-great-grandniecemug. Sibling's great-great-great-granddaughter.
My great-great-great-grandniece is a good person.
by Gtopql November 23, 2019
Get the great-great-great-grandniecemug. Spouse's great-great-grandnephew's wife.
My co-great-great-grandniece-in-law is a good person.
by JAMP12 September 21, 2021
Get the co-great-great-grandniece-in-lawmug. 
Get the 6X-grandniecemug.