Introducing a woman, Anjali says, 'She is the wife of my daughter's only brother.' How is that woman related to Anjali?

Introduction / Context:
This problem tests your understanding of in-law relationships. Anjali introduces a woman by describing her as the wife of my daughter's only brother. You must track who my daughter's only brother is and then see how his wife is related to Anjali. The scenario is a classic way of arriving at the relationship daughter-in-law.

Given Data / Assumptions:
- Speaker: Anjali. - Anjali has a daughter. - That daughter has exactly one brother, called her only brother. - The introduced woman is the wife of this only brother. - Standard nuclear-family relationships are assumed.

Concept / Approach:
First identify my daughter's only brother. In a typical family, if a woman has children including a daughter and a son, then the daughter's only brother is that same son. From Anjali's viewpoint, my daughter's only brother is Anjali's son. The introduced woman is the wife of this son. Therefore, she is Anjali's daughter-in-law. The problem is essentially asking how the wife of one's son is related to one.

Step-by-Step Solution:
Step 1: Let Anjali's daughter be D. Step 2: D's only brother is Anjali's son S. He is the only male child of Anjali in that generation. Step 3: The woman being introduced is the wife of S, that is, she is married to Anjali's son. Step 4: In family terminology, the wife of one's son is called one's daughter-in-law. Step 5: Therefore, Anjali is the woman's mother-in-law, and the woman is Anjali's daughter-in-law.

Verification / Alternative check:
Draw a small family tree: place Anjali at the top, with two children: a daughter D and a son S. Then connect S to his wife W. W's relationship to Anjali is via S: W is the spouse of Anjali's son. From W's point of view, Anjali is her mother-in-law. From Anjali's point of view, W is her daughter-in-law. No other relation such as niece or sister fits this pattern.

Why Other Options Are Wrong:
- Niece: A niece is the daughter of a sibling or of a sibling-in-law, not the wife of one's son. - Sister: A sister would share parents with Anjali, which is not indicated. - Cousin: A cousin shares grandparents with Anjali, which is also not stated. - Aunt: An aunt is a sister of a parent or the wife of an uncle, a generation above, not someone in the child's generation married to the child.

Common Pitfalls:
Students sometimes misread daughter's only brother as son-in-law, but that is a different relationship entirely. The phrase clearly points to Anjali's own son, not to a spouse of the daughter. Another common error is to reverse the direction and answer mother-in-law instead of daughter-in-law. The question asks How is the woman related to Anjali?, so the correct term must describe the woman from Anjali's perspective.

Final Answer:
The woman is Anjali's daughter-in-law.