You might, but you might not. Remember that your great grandmother contributed only about one eighth (1/8) of your genetic makeup.
You add another "great" for each generation back in history. So the mother of your great great great grandmother is your great great great great grandmother.
You grandmother's father is your great grandfather and his wife (your grandmother's mother) is your great grandmother.
Your great grandmother's sister is your great-great-aunt.
The English language does not include a relationship called "great mother." It has terms "grandmother" (the mother of your father or of your mother) and great grandmother (the mother of one of your grandparents. The sister of your grandmother is your great aunt. The sister of your great grandmother is your great great aunt.
She could be your grandmother. Or she could be your great aunt.
Its possible. My great-uncle and great-aunt were twins. I could have been a twin, but I am not.
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Your grandmother's grandmother is your great-great-grandmother.
Your great grandmother's mother is your great great grandmother.
Tatarabuela Grandmother: abuela Great grandmother: bisabuela Great great grandmother: tatarabuela
You add another "great" for each generation back in history. So the mother of your great great great grandmother is your great great great great grandmother.
your great great grandmother.
Your great grandmother's brother is your great great uncle.
You grandmother's father is your great grandfather and his wife (your grandmother's mother) is your great grandmother.
Ruth was the great grandmother of King David.
Your great grandmother's sister is your great-great-aunt.
The singular form of great-grandmother is great-grandmother.