I've taught young kids to needle felt...which is felting wool with a sharp barbed needle and poking the object a thousand times.
I believe if you explain safety to a kid and tell them how serious it is and how easy it is to get hurt then you shouldn't have any issues. I think once a kid realizes how serious it is they treat it serious. And make sure to monitor them, don't just give it to them and expect them not to possibly make a mistake. (not saying you would )
Also I believe there are some rotary cutters out there with a safety...maybe it would be a good idea to invest in one of those for her.