Do not get a bark collar, those things are fucking cruel.
Just get a water bottle, have some one come over just for this, and every time she barks spray her. But be careful not to turn it into a game. I did that with a cat I had a long time ago and it turned into the chase game.
You can also add some vinegar too the water. They do not like that!!
I would plan for someone to come over a lot at first. Plus have it be a different person sometimes so she doesn't get use to that one person.
Edit* What m00d said is good too!!
