My son has a very nice wife - we love her and (I think!) she loves us, so there is no animosity underpinning this query. I'm just curious as to how others would approach it.
Son and DIL have very busy, full on lives - both have jobs with long hours, three young children, large chaotic renovation project house. My husband and I provide them with a lot of help and support - regular childcare commitment for the younger two children (and the eldest in the school holidays), and a couple of weekends a month they invite us for lunch and we usually help them with something like a DIY project. I also often do their ironing. My husband and I don't resent this at all. We love the children and appreciate the time we get with them, and we are both retired so have lots of spare time which we don't mind spending helping them out. It's generally a happy, friendly family arrangement which we all enjoy.
DIL has recently started giving us random presents as thank yous for this help - not big things, but candles, vouchers, flowers etc. It's not every time we help but it's about once a month. I've told her it's very kind but not necessary to her face and have also told my son she doesn't need to feel obliged to do this - we really are happy to help. He said it makes her feel better and like she's not taking advantage, but to me it almost feels transactional, like she's paying for the help. I'd rather she just accepted it as something families do out of love rather than being done in the expectation of a reward.
Would you raise it with her again and say it really is unnecessary, or would you just accept it's her way and accept the gifts with thanks?
(Aware this is not a juicy problem by mumsnet standards)