I agree with Connemara, you need to take charge. If she refuses to listen to you she should be dropped from the program. No 8 year old should be grooming and tacking without second by second supervision. (unless they are one of those rare horse kids who started when they were 5 and actually know what they are doing) At our barn I supervise everyone until I am completely convinced they know what they are doing and even then I double check to make sure feet are properly picked up, bridle and saddle properly adjusted, etc. And those are for adults and kids a like of all ages.
Sounds like this program does not provide enough structure or supervision.