From (i): A is the mother of B. So, A → B's mother.
From (ii): C is the son of A. That means A has at least two children: B and C.
From (iv): E is the daughter of B. So, B is the parent of E.
From (iii): D is the brother of E. That means D and E are siblings, both children of B.
Hence, B is the parent of D. And A is the mother of B. Therefore, A is the grandmother of D.