Josephine, I would continue the supervised play time in the bath room.  If
there is no serious biting going on, it sounds like it's going fine.
Hissing and screeching are just hard on your nerves, but are not going to
hurt the ferrets.  If the girls are bouncing and dooking in the midst of
their posturing, the conflict can't be too serious.  I would continue to
pick them up and talk softly to them while holding them both.  Hissing
means they're scared and trying to look tough so comfort them and let them
go at it again.  I don't think you should leave them alone in the bathroom,
they may feel abandoned, just continue to supervise.  They may never be
best buddies, but as long as they aren't hurting each other, let them
scream.  I have an older female who hates other ferrets, esp.  males and
though I can put my baby boy in the cage with her and the other girl, she
does protest.  In fact, if she smells a strange ferret( I foster them) she
will even nip her female room mate, who she has been with for over three
years!  But they don't hurt each other.  It sounds like yours are just
doing instinctual ferret posturing to establish dominance.
 
Good luck, be patient and hang in there.
 
Lara Smokey, Chaos and Baby, with Phantom the foster and 'Scratchy' the
backyard boy.
[Posted in FML issue 2494]