I used to go to a lot of trouble to collect gifts for these same nieces and granddaughters. MY nieces and granddaughters always wrote thankyou notes. My husbands nieces only occasionally would thank us for their gifts. This always rubbed me a little the wrong way because my MIL used to correct me on manners and she told me that it was ok to thank someone in person but to always follow up with a written note. These nieces belong to my husbands only sister who was raised by this same MIL. You would think she would have taught her daughters these manners. I sent a baby quilt to one of these nieces and my SIL put a pic on facebook of the baby wrapped in the quilt. But I don't recall anyone saying thank you. Certainely the niece didn't. This has always upset me and I would have stopped sending them gifts a long time ago except for my DH who enjoyed me sending them. I did manage to stop sending them Christmas gifts a couple of years ago. I told them I was using the money I spent on gifts for nieces and grand children to buy Christmas gifts for needy kids in the school where I sub. Which I did do. The quilt is the only gift I have sent since. It was for my SIL first grandbaby.