Would you knit any more gifts?

I love knitting and have recently had a grand niece. So far I have knitted a pram blanket and a jacket. But since I sent them to the couple, together with a pram toy and two other bought outfits, I haven't had any acknowledgement. This was over a month ago.
The baby is my sister's son's child. My sister was upset that the couple haven't so far said thank you for any of the gifts they received, and so she posted thank you cards herself, pretending they came from the couple. I got one myself, but it didn't make me feel much better, since I know it didn't come from the couple themselves.
She did this because a lot of people complained they had not been thanked for the couple's wedding presents, over five years ago. No one got a thank you, not even a text.
My dilemma is, I have lots of left over yarn and I could knit more baby clothes but I feel they are not appreciated.
Am I being precious, or am I right to feel offended? Do young couples actually want hand knitted clothes anyway?