Fold paper multiple times and punch holes in uniform manner. Now open the paper, place it on an empty sheet and ask your child to colour all over the top one. When finished, remove the stencil paper and show her the pattern in which paint was smeared on the bottom sheet. Explain the same by showing her the holes on the stencil sheet and dots on the bottom one.
You could make stencils of various shapes/objects by simple cutting. I tried making a diamond, a rectangle and an ice cream.