JR attacking our other dog

Question
QUESTION: We have a yr old female JR, she has always growled and nipped at the other two dogs when they try to go in or outside. The other night she completely attacked Kendall, our golden mix, out of the blue and for no reason that we could see.the fight went on for a few minutes and the JR ended up with a hole in her throat and a puncture on her neck. The other night I was sitting on a chair and kendall came up to me and JR went right into attack mode, not the playful attack that is quite normal in our house.2 days later she still wants to attack kendall and i am scared to have both of them in the room at the same time. They played together all the time before the attack, we could tell by the growling when things were getting a bit out of hand and we would make them take a break. up until the other day we have not had any problems like this. How do we correct this. I live in a small town and I'm not sure we have a behavior trainer. Also she is growling and snapping at us when she is getting ready to sleep and we move her, sometimes all we have to do is pet her. we can tell that she knows what she's doing is wrong, but it's almost like she can't stop herself. If you have any suggestions it would really help

ANSWER: Hi Sally,
It's better late than never but you definitely have to get a professional trainer involved now. The time to train her OUT of aggression was when she first came into the house. She definitely feels as though she is the pack leader/dominant one in the home. There is NO WAY she should be growling at anyone but especially YOU.
Unfortunately once a pair of dogs reach that attack stage, it's very hard to keep it from happening again. I suspect it's jealousy on the part of the jack and absolutely should not be allowed. You might have to travel a bit, but it would be even better if you could have a trainer come to your home so that they can see the two in action.
Sorry you have to go through this, good luck!

---------- FOLLOW-UP ----------

QUESTION: She wasn't like this like I said up unitl 2 days ago with the other dog attack and maybe a month or so for the growling at us. Could something be wrong with her that we don't know because she wasn't aggressive up until now.

Answer
Oh, I see, but you said she has "always" nipped at the other two dogs, so I assumed it was an ongoing thing. If this is a new behavior then you could be right, she could be in pain or something. It's so very hard to know these things without actually seeing her. You could take her to the vet for a good physical just to be sure.
Again good luck Sally, hope you can get to the bottom of it.
Take care