Let the lady in the photograph be X.
According to Sujata: "Her son's father is the son-in-law of my mother."
Breaking down "Her son's father":
- This refers to the lady X's husband
Breaking down "son-in-law of my mother":
- A son-in-law is a man married to someone's daughter
- Sujata's mother's son-in-law is the man married to Sujata's mother's daughter
Combining both parts:
Lady X's husband = Sujata's mother's son-in-law
This means lady X's husband is married to a daughter of Sujata's mother.
Since lady X is married to this man (who is Sujata's mother's son-in-law), lady X must be a daughter of Sujata's mother.
If lady X is a daughter of Sujata's mother, and Sujata is also a daughter of Sujata's mother, then lady X and Sujata are daughters of the same mother.
Since Sujata is referring to "the lady" as a different person, the lady must be Sujata's sister.
Therefore, Sujata is the lady's Sister.
The correct answer is Option 2: Sister.