Ok i have used this with my puppy who is not 8mnths old and i can say it has helped.When your puppy tries to bite,you can 1.Clap ur hands loudly 2. make the psst sound 3. ignore her till she stops.
With whichever one that you find that woprkd for ur puppy, and she calms down (stops bitting) praise her calmly with a treat. Hope this helps!!