This is a great idea for any sort of DIY artwork: trace a simple graphic onto three canvases, and paint. So much more esthetically pleasing than if you were to just trace and paint onto one canvas. Plus i love the whale idea for a little boy room :)
DIY Woven Friendship Bracelet Using a Circular Cardboard Loom. Very easy, cool jewelry craft for kids weaving a seven strand friendship bracelet. Tutorial from Michael Ann Made here. This might be a good summer craft for the older kids.
DIY Safety Pin Bracelet 80 safety pins Beads Elastic cording Place beads on pin as desire. After you have beaded all your pins thread them onto two elastic strings equal in length. Alternate the tops and bottoms of the pins.