There are seven members in a family. J is the mother of K and mother-in-law of…

Concept: In blood-relation puzzles, compound relational terms such as mother-in-law, daughter-in-law, and spouse must first be decoded into direct parent-child or sibling links using the genders and family structure given in the puzzle; only then can the target relation be read off the resulting family tree.

Application:

1. C is the daughter-in-law of N, so C is the wife of one of N's sons.

2. E is the son of C, who is married to F, so F is C's husband (and therefore N's son), and E is the son of C and F.

3. G is the spouse of E. Since E is male, G is E's wife.

4. J is the mother-in-law of E, which means J is the mother of E's wife — so J is the mother of G.

5. J is also the mother of K, so G and K are siblings, both children of J.

6. Only two married couples exist in the family: C and F, and E and G — consistent with all the clues given.

Cross-check: Counting the family tree built above — J, K, E, C, N, F, G — gives exactly seven members, matching the stem's statement of seven family members, confirming the tree is complete and correctly built.

Therefore, G is the daughter of J.