It's DD1's 5th birthday today. Every year on one of the DDs birthdays DH's nan (I.E, our DDs great-nan) gives the girls a card with some money in. She's well into her 80's now and clearly getting more confused. When we opened DD1's card pile this morning we realised DH's nan has accidentally sent her two cards, both with £10 in, obviously having written the second after forgetting she had already written one. I genuinely don't know whether it's kinder to return one of the £10 notes or whether that would just be embarrassing for her? But I feel uncomfortable keeping two lots of birthday money for DD when one set was obviously given in error.