If $X$ is the brother of the son of $Y$'s son,how is $X$ related to $Y$?

Pointing to a photograph,Vipul said,"She is the daughter of my grandfather's only son." How is Vipul related to the girl in the photograph?

Pointing to a man in a photograph,a woman said,'His brother's father is the only son of my grandfather'. How is the woman related to the man in the photograph?

$P$ is the son of $Q$,while $Q$ and $R$ are sisters. $T$ is the mother of $R$. If $S$ is the son of $T$,which of the following statements is correct?

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 $B$. How many male members are there in the family?

In a family,there are six members $A, B, C, D, E$ and $F$. $A$ and $B$ are a married couple,$A$ being the male member. $D$ is the only son of $C$,who is the brother of $A$. $E$ is the sister of $D$. $B$ is the daughter-in-law of $F$,whose husband has died.
How is $F$ related to $A$?