Pointing to a man,a woman said,"His mother is the only daughter of my mother." How is the woman related to the man?

$A$ family consists of six members $P, Q, R, S, T,$ and $U.$ There are two married couples. $Q$ is a doctor and the father of $T.$ $U$ is the grandfather of $R$ and is a contractor. $S$ is the grandmother of $T$ and is a housewife. There is one doctor,one contractor,one nurse,one housewife,and two students in the family. Who is the sister of $T?$

Pointing to a photograph,a man tells his friend,'She is the daughter of the only son of my father's wife'. How is the girl in the photograph related to the man?

There is a family of six persons $A, B, C, D, E,$ and $F$. They are Lawyer,Doctor,Teacher,Salesman,Engineer,and Accountant. There are two married couples in the family. $D$,the Salesman,is married to the Lady Teacher. The Doctor is married to the Lawyer. $F$,the Accountant,is the son of $B$ and brother of $E$. $C$,the Lawyer,is the daughter-in-law of $A$. $E$ is the unmarried Engineer. $A$ is the grandmother of $F$. What is the profession of $B$?

$A$ 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 is $E$ related to $F$?

Pointing to a boy,Seema said,"He is the son of my grandfather's only child". How is the boy related to Seema?