How old is the guinea
How long have you had her
Can you get her to a vet asap, yes it would be an emergency call out
Please take her away from the rabbit, the rabbit can cause her serious injury, and may have done so, which is what is causing the breathing trouble
Is she drinking and eating, or moving around by herself at all?
She either has an Upper respiratory infection, or she could have been damaged by the rabbit, I would advise you get her to the vet
Hope she's OK.... fingers crossed