> removing her from her puppies might upset her more than the fireworks!!
It depends how she normally reacts to fireworks, which is why I said "if she really panics". I've had dogs that just look a bit worried, maybe pant a bit at fireworks, fine, but I've also had several (collies) that panic so much they try and hide at all costs, digging through sofas and walls, completely oblivious to my attempts to calm them, if she's going to panic like that she probably shouldn't be in with the pups.
When is the event? I've had great results with Xylkene, it's milk powder based I think so I can't imagine it does any harm to lactating bitch but check with your vet. Unfortunately it takes a week or so to build up so may not be any good in these circumstances. When I had collies I would start them on xylkene mid october to get them through fireworks season.