When I was doing after school care, there was always a need for a simple activity at the end of the day that could be worked on individually, and put away whenever the parent arrived. Needlepoint turned out to be a good activity for the girls in grades 3 and up. They could keep their project in a zip lock bag with their name on it, work at their leisure, and chat with the other girls while they worked.
One of the projects they made was the heart necklace pictured. Cut two hearts from scraps of plastic needlepoint canvas, as large or as small as the scraps allow. The easiest way to cut the shape is to draw the design on the canvas with a permanent marker.
There is a special kind of yarn for plastic canvas, but any kind of four-ply yarn can be used. Work the entire area with a Continental stitch. Whip stitch the edges.
The design pictured has two hearts joined with ribbon that is sewn through the worked design and then tied in a bow. The hearts could also be stacked on top of each other, sewing the ribbon through the center like a button, and then tied in a bow.
Finish the necklace by sewing a piece of thin ribbon under the stitches on the back of the heart. Tie the ends together with an overhand knot.