A.M.
I would say incorporating the children's help to make something would be a meaningful gift. Going to one of the clay art studios and maybe making her a plate with their handprints (top it with some special snacks and treats) or a special coffee mug (in a basket or bag with some yummy coffees). Most places can give you ideas and help you make it look pretty if you're not crafty. This way she has something to enjoy now and then has the keepsake to remind her later of your children.