First cousin's great-granddaughter.
My great-great-cousin-niece is a good girl.
Sesqui-first cousin’s granddaughter.
My sesqui-first great-cousin-niece is a good person.
1. The daughter-in-law of one's sibling.
2. The daughter of one's spouse's sibling.
My niece-in-law is a good person.
1- Nibling's wife.
2- Spouse's niece.
My niece-in-law is a good person.