I give gifts not for the thank yous, but because I like to give.. That being said, I at least want to know the gift was received, so I do call if I have not heard from anyone in that home...
The fact that even the adults do not send Thank you notes says it all.. How are the children supposed to know if their parents do not do this themselves?
Does your husband write all of his thank you notes?
I know my husband does not.. I do, so does our daughter, but my husbands family NEVER writes thank yous.. At least now with email I can send and email and just ask if the gifts were received.
This last Christmas my sister asked me to please give her son, my nephew personalized notes.. I gave him more exciting things as well as beautiful personalized cards and envelopes and a special pen. He was so excited.. He will be a junior in high school this year, so he wanted some more grown up notes..
Maybe this could be your next gift to them.. Maybe they do not have any thank you notes? Hee, hee..
Just call or email to make sure they were received and in the future keep your expectations low, they may surprise you.. I still give gifts to my inlaws, I just know they will never send a thank you..