What gift did you give your mother-in-law (aside from a grandchild haha) that she really appreciated?

Hi, I think the biggest gift is the grandchild. Why would you wan to gift her other than that? Rather she should be gifting you for the cute little bundle of joy all her life. Anyway, on a serious note, you can gift her depending upon her like. If she is a book lover, gift her favourite author's book. Or if budget is not a problem, book a holiday for her along with one other person she would like to take along. Or some personalised gift like, a hand-knitted sweater or something like that.