My grandma taught me how to sew, she sat me on her lap to start with and she operated the pedal and helped me guide the fabric thru. I still remember the day I was big enough to operate the pedal. I did the same thing with my daughter putting the machine on slow. (She is not a seamstress but does know the basic skills!!)
As far as hand sewing she taught me the correct way to do the basic running stitch at an early age and let me make my own mistakes. I did prick my fingers a good many times!!
So the moral is: teach her the right way to do things but keep a close eye on her!