Question

नानी की इकलौती संतान = लड़की की माँ। माँ का पिता = लड़की का नाना। नाना का पोता (Grandson of maternal grandfather through the son is cousin, but through the daughter it's her own brother. Wait. If the mother is the only child, the grandfather has no sons. The grandson of the grandfather must be the son of his only daughter (the mother). Therefore, the boy is the son of the girl's mother, which means he is her भाई (Brother). / Maternal grandmother's only child is the girl's mother. Father of the mother is the maternal grandfather. Since the mother is the ONLY child, the grandson of the grandfather can only be the son of this mother. Thus, the boy is the girl's own brother.