They would be your second cousin. Your great aunt is the sister of one of your grandparents. Your parents and the granddaughter's parents are first cousins.
First cousins, twice removed.
Aunts daughter is your cousin.
Aunts daughters daughter is cousin once removed
Aunts daughters daughters daughter is cousin twice removed.
Your aunt's grandchild is your first cousin once removed
She is still considered to be your niece. But she is the daughter of your cousin, to be exact!
Your great great grandfatehr's sister is your great great aunt. Her granddaughter is your parent's second cousin and yoursecond cousin, once removed.
Your grandmother's granddaughter is one of the following:
you are related to her.
Great Great Cousin
First cousins, twice removed. Aunts daughter is your cousin. Aunts daughters daughter is cousin once removed Aunts daughters daughters daughter is cousin twice removed.
No relationship at all, you don't share a common ancestor.
Your sister is her great grandaunt.
Your brothers great granddaughter is your great great niece.
Your granddaughter is your sister's great niece. Your sister is your granddaughter's great aunt.
Your sister is the great-aunt (also written great aunt) of your granddaughter.
your niece
Your uncle's great granddaughter is your first cousin, twice removed.
Your niece's granddaughter is your great great niece. You are her great great aunt (if you are a woman) or her great great uncle (if you are a man).
great aunt
Your great aunt is the sister of your great grandparent. Her granddaughter is your second cousin and her great granddaughter is your second cousin, once removed.
Your aunt is great great aunt to your son's daughter (your granddaughter). Your granddaughter is your aunt's great great niece.