A bit of a delicate situation. My best friend has 2 teenager daughters, neither of whom say so much as "thank you" when I send them birthday/Christmas presents. In the past, I would always ask her what the girls would like for presents and friend would give me a few ideas. But in last couple of years I've stopped bothering to ask because I never get a thank you anyway. The girls have quite niche hobbies, so presents were usually centered around those. I'd order from specialist suppliers. It ended up being expensive and totally thankless so I've just started to send them a bit of chocolate and bath sets etc. AIBU to think it's just rude not to say thank you? My own kids are the same age as hers and I've always made sure they either write or message people to say thank you for gifts.