What is puppy nipping? They are not herding you, although this play may be teaching them how to herd. They are not aggressive, either. They are simply being puppies, and that means play-biting.
This is very normal and NOT aggressive. Aussies are a nippy breed as puppies.
They DO grow out of it and there isn’t much to be done, but there are a few things: don’t run, scream, etc. because this seems like a game. What should be done is stop what you are doing. Wait for the puppy to stop being so bratty, ignoring her for that behavior, and then praise when she’s good. “No” and unlocking a biting puppy won’t work, its more of the game to your rascally puppy.
Like I said, time will take care of it. Watch your puppy around three months, when she starts chewing because of her teething, it can get bad at that time, but once it passes, you are out of the water!