AIBU not to give my nephew and niece Christmas presents?

[BikeRunSki]

They are 12 and 8 respectively.
They live abroad, and their mother (my sister) is very, very label/image conscious wrt to everything they have. It is increasingly difficult to get them anything "acceptable". For the last two years I have not had any thanks or aknowledgement of their presents. DNeph had a birthday recently. DSis told me he needed a new hoody, and to get something from Abercrombie and Fitch.I am not in that kind if league atvall, so.I sent him some money - the equivalent of £25. I know he got it because when DM asked DSis about it, she dismissed it as "not really worth thanking for".

My children are much younger and DSis's presents to them are not un-generous, but always OTT. Eg DS wanted his own copy of a particular Julia Donaldson book for his birthday. So she sent him that, and 4 or 6 other books he already had. DD (1) needed some winter clothes, so she sent designer frilly stuff, rather than anything at all practical. That sounds really ungrateful doesn't it? But I do always write and thank her!

We rarely speak and I maintain a skeleton relationship with her primarily for DM's sake. We are very, very different people, and if I met her at a party for example,, then we wouldn't become friends. Our relationship wavers between ambivalent and toxic (she is queen of passive aggressive).

I know I should not blight DNeph and DNiece with my history with their mother, but the expectation and lack of gratitude are really peeing me off. And DSis does not send OTT presents to be generous, she does it to show off that she can.

VonHerrBurton You have summed up my sister's various character traits perfectly. Seriously, even my mother wonders how we share the same DNA and upbringing. We fall out a lot and I promised 2 years ago never to spend the night under the same roof as her again.

CuttingPiccassosToenails DSis did not realise that I ws with DM and she was on speaker phone when she said that. DM was mortified.

I can't bear people who don't send thank you cards. I love Xmas and put a lot of effort in, it makes me so cross when I send pressies in the post and the recipient doesn't even acknowledge it so I don't know if it's got to them. Grrrrr...
As for your sister, she sounds superficial and like she's raising her kids to be very ungrateful. I would send something like an age-appropriate book and a nice hat or top, something that isn't likely to not be their cup of tea. And I'd definitely bring up the lack of a thank you with your sister - maybe contacting her to check if the presents arrived as you've not recieved a thank you letter?
Good luck - she sounds like a nightmare. My relationship with my sister is similar, although she is the opposite of your sister in terms of successful job, label addict etc. She's a total hippy but equally self-absorbed!

I'm sitting here cringing as my dc's are teens, and can be very greedy and grasping! I've suggested they think about what they might like for presents, and found out later that they have sent out emails with a list of demands suggestions.
Obviously we had words I was horrified!
So my suggestion is buy them something small, inexpensive and don't worry. Frankly mine are old enough to deal with only getting a small gift, and I give to my dn's without any expectation. I give to give ...not so my kids receive.