Since no one here can actually see your dog, it is hard to tell just what is going on. If your dog is relatively young, she may be trying to "play fight". This is a way dogs play in a somewhat rough manner, usually amongst one another while puppies. When there is no other puppy or dog available, they will play in the same manner with a friend human.
You might see the dog jumping, bowing, growling, running around, etc. Sometimes the dog will also "play bite" which, again, is not an aggressive act, but play.
Look up "play fighting in dogs" and play biting in dogs" to see if your dog is doing this. Usually they are wagging their tails during these activities, so it is relatively easy to see they are not trying to harm you,
There are also videos that show what to do for play biting. DO NOT yell at the dog, or hit/flick the dog. Usually, keeping your hands away from the dog, and trying to settle the dog down will help.