I don't want to sound mean but....
Teach her the proper way to do it with as small of stitches as she can manage. Tell her the smaller the better. After a few minor pin pricks she'll learn. We can't protect them from every little hurt as much as we want to. Let her learn and part of the learning is learning not to stick yourself.
Just give her some thimbles and keep encouraging her. Tell her that it will be so beautiful when she gets it done and that yes, it takes a long time but it's worth every minute.
Every read the story about the butterfly struggling to get out of the cocoon? All the hard work needed to get out also helps them develop so that they can fly. If you open it for them they die. Allow your "butterfly" to develop so that she can fly.