FLG: I would not say anything to the DIL, sons, etc.

What I would do is the following: next time you are watching the grandchildren, take lots of pictures and post them on YOUR FB!

Here is a nifty thing you can use if you have an iPhone (I do not):

http://www.containerstore.com/shop/s...uctId=11000122

If you have an iPhone, get the thingie in bright pink and take pictures of yourself with the grandchildren. At home and outside- both. Just hanging out or doing crafts. And do that every time they visit with you.