Sorry to hear of your family’s loss. It always hurts.
I went through 7 miscarriages over the span of ten years, and it’s a very private loss that is hard to share with others. My best advice is to do things for your daughter-in-law. Bring her goodies or a gift certificate for a therapeutic massage. Pay for a housekeeper to come in if she would like that. If you’re close, take her to lunch and shopping.
I lost one baby literally while attending a baby shower for a very dear friend. Oddly, it was the easiest to bear, because I was busy making sure I didn’t ruin her special day, so it gave me some purpose, some reason to bear up under my own pain. She thought I left early because of feeling ill; she never knew why I really had to leave.
In taking action to comfort your daughter-in-law, it will put your own grief in motion for good and help you move on.