I have found with Campbells they are either nippy or they aren't. Some are worse than others and they seem to use their teeth to investigate more than other breeds.
Have you tried putting her in an exercise ball for a short while before handling her.
Also when they do nip try blowing gently into their face so they learn nipping brings something unpleasant. It may take a couple of weeks but your Campbells should hopefully soon learn.
Good Luck