grandmother-in-law
A grandmother of one's spouse.
My grandmother-in-law is a good person.
great-grandmother-in-law
The great-grandmother of one's spouse.
My great-grandmother-in-law is a good person.
great-great-great-grandmother-in-law
Spouse's great-great-great-grandmother.
My great-great-great-grandmother-in-law is a good person.
great-great-grandmother-in-law
The great-great-grandmother of one's spouse.
My great-great-grandmother-in-law is a good person.