One grandmother used to buy for all the grandkids. As she got older and driving was an issue, she started giving $10 to each one in a card. The other grandmother gave $20 or a gift card to each one. My stepgreat grandmother (all grandkids were steps) gave each gt grandchild $5 in a card.
Now, that we're all adults, most with kids of our own, we ask my grandmothers (both in their 90s) not to give money to any of us but to use it on herself. Doesn't matter cause they still give money to all the kids, grandkids, and gt grandkids...which quickly adds up with so many of us. So that it's not taking money away that they may need the following month (on limited incomes), my cousins and I all buy them gift cards for grocery stores, pay a utility bill etc for them the following month.