Yes, your great grandmother's sister is your great-great aunt. Your great aunt is your grandmother's sister.
Your grandmother's sister is your great-aunt.
Marrie Carrie was named after her grandmother and her grandmothers sister (great aunt)
You are your neice's aunt, your neice's children's great aunt, and your neice's grandchildren's great great aunt
Your grandmother's sister is your great aunt
A great great aunt is the sister of your great grandmother. (A great aunt would be the sister of your grandmother.)
Your great grandmother's sister is your great great aunt (or some would say, your great grand aunt).
Your grandmother's sister-in-law is your great aunt and your grandson's great great great aunt.
Your mother's sister's aunt is also your mother's aunt. So she would be your great aunt.
She would be his Great Aunt
Your sister would be her great aunt and she would be your sisters great niece.
You would be his Great Uncle or Great Aunt He in turn would be your Great Nephew.
Your great grandmother's sister is your great-great-aunt.