At this year's Highland Gathering and Games, we bought my five-year-old a toy archery set: a "bow" made from bent schedule 40 PVC with a foam handgrip, a mailing-tube quiver, and six "arrows" made from notched dowels with eraser tips. She was extremely excited (her older friends got them last year), and wanted me to set up targets for her when we returned.
This is the result. I had some shelving strips left over, and used two 1 m long for the sides, and two 70 m for the cross pieces. To keep the frame standing, I put two of the shelf supports upside down at the bottom (second image), and bent the tabs (third image) so they couldn't move or fall out. Add two big bulldog clips at the top (fourth image) and bottom, and my little archer can get practicing!