Valentine bookmark craft kit from Kazsmom on Etsy. Looks like hearts laminated between two lamination sheets to me, with hole punched in the top for a ribbon. Could change up from hearts to Christmas trees, or Christmas star and such.
Origami is a little tricky for them because they don't have the dexterity, but with a little help they made origami bookmarks and christmas trees as an activity. They had fun with it. Folded Paper Heart Book Page Marker – DIY