I really don't think that you should trade your ferret back for another
one.  My ferret when we got him was the same way but in a few weeks he has
learn to nip a lot lighter so he dosen't break skin.  I think all she needs
is time to adjust to her new place.  How long have you had her?  Also if
you are trying to pick her up or touch her while she is eating then she
will bite you hard.  Kits sometimes become very protective of their food
and this is just a phase.  I guess my suggestion to you is that trading her
wouldn't do anything you might just end up with another nipping ferret.
Just be patient and consistent with your training and remember she is baby
with lots of energy to burn.  Maybe get her a stuff toy smaller then her to
rough play with.  Just make sure she's not chewing it and eating the pieces
of it.
 
See ya
[Posted in FML issue 3215]