Pointing to a girl in the photograph,Amar said,"Her mother's brother is the only son of my mother's father." How is the girl's mother related to Amar?

Introducing a man,a woman said,"He is the only son of my mother's mother." How is the woman related to the man?

$A$ is the son of $B$; $C$,$B$'s sister,has a son $D$ and a daughter $E$; $F$ is the maternal uncle of $D$. How many nephews does $F$ have?

All the six members of a family $A, B, C, D, E$ and $F$ are travelling together. $B$ is the son of $C$ but $C$ is not the mother of $B$. $A$ and $C$ are a married couple. $E$ is the brother of $C$. $D$ is the daughter of $A$. $F$ is the brother of $B$. Who is the wife of $E$?

Introducing a man to her husband,a woman said,"his brother's father is the only son of my grandfather." How is the woman related to this man?

Pointing to a photograph,a person tells his friend,"She is the granddaughter of the elder brother of my father." How is the girl in the photograph related to the person?