Susan Rooney Lewis
You granddaughter is a great great niece of your aunt. Your aunt is your granddaughter's great great aunt.
Example: Great-great-great Granddaughter Katie
Your granddaughter is your sister's great niece. Your sister is your granddaughter's great aunt.
Your sister is her great grandaunt.
Your brothers great granddaughter is your great great niece.
Your sister's daughter is your niece. Your sister's granddaughter is your great niece Your sister's granddaughter's daughter (your sister's great 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.
Step-great-granddaughter
granddaughter
Your great uncle's granddaughter is your second cousin.
The word is "bisnieta". Note that "nieta" alone means "granddaughter".
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 grandmother's brother is your great uncle. Your great uncle's son's great granddaughter is your great uncle's great great granddaughter. Your great uncle's great great granddaughter is your second cousin, twice removed, and is your daughter's third cousin, once removed.