(A) A, B, C, D, E and F are six members of a family.
(B) One couple has parents and their children in the family.
(C) A is the son of C and E is daughter of A.
(D) D is daughter of F who is mother of E.
Analysis Summary: From (C): C is parent of A (male), A is parent of E (female). From (D): F (female) is mother of D (female) and E (female). Combine (C)+(D): A is father of E, F is mother of E
=> A and F are the couple (A=husband, F=wife). Dand Eare their daughters (children). From (C), C is parent of A. From (B), the couple (A,F) has parents in the family. So, C is one grandparent.
The other must be B. Family: Grandparents (B, C, parents of A), Parents (A, F), Children (D, E). Gender: A(M), F(F), D(F), E(F). B/C are one M, one F.