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.
Your great grandmother's sister is your great-great-aunt.
The daughter of your husband's brother is your niece.
Half-Sister Cousins
The relationship of the sibling of your sister-in-law or brother-in-law to you does not have a name in English. You could call them your brother- or sister-in-law if you want, or you can call them the brother or sister of your brother- or sister-in-law.
Yes, they are related directly to you. They are your mothers sister. And your father's sisters.
cousin
Mom
In Hindi, you would call your mother's sister "mausi" or "masi".
your great great grandmother.
Our cousins are our mothers sisters son :)
In Arabic, you would refer to your mother's sister as "خالة" (khala).
Your great grandfather
His relationship to you is brother-in-law.
Your mothers sister is your Aunt
Mothers sister is aunt and son is cousin so daughter wouldn't that be a niece
A gatecrasher.
your great aunt.