It was pretty simple, as projects go: cut out rectangle of cloth, sew up on all sides except for a small area, turn inside out, use funnel to fill with rice, sew closed. What you do is take this item and microwave it for about a minute - the rice heats up and then the bag can be used (and reused) as a heating pad. There are commercial ones available with flax seed or buckwheat, but plain wheat or rice works too.
An early holiday gift. If I were really clever I would have taken a picture before giving it to her, but there you go.