I let her put a dab of glue between the petals and I help her center them:) Rotate them so the petals fall between the one under it. We just used three circles of different sizes with petal cuts out of each one.
Once she placed them how she wanted them I came in with the needle, thread and button off of one of Daddy's shirts and secured them together.
She found the perfect place on the headband to place the flower and I stitched it on for her. She loves the headband "she made".
Sometimes with crafts for preschoolers it's more about letting them guide the work and fully giving them the sense of accomplishment. That feeling of "I made this" is just really really cool:)
We also made up some with pom poms we had left over. Sometimes we go on a pom pom making kick around here...just because we can.