With Tobie I started out praising him after only about 10 seconds of quiet and then each time I would increase the amount of time he needed to be quiet. That way they start to slowly make the connection - "when I'm quiet I get attention". It does take patience but it really did work for Tobie.
With the biting it sounds like you are doing the right thing with folding your arms and turning away from her. She will learn that she gets ignored when she is misbehaving. Just make sure to praise her as soon as she stops and then if she starts biting again then turn away from her. If this just is not working at all then I would definitely have a designated "time out" area. We have also had to do this with Tobie when he bites at the other dogs ears and legs. It usually only takes one or two "time-outs" before he stops.
Puppies are exhausting, huh? LOL. It's so worth it though when they catch on and all of your hard work pays off
