Oh, I forgot to mention, we got her as a stray before I even knew what breed she was; the home she wandered up to was owned by a co-worker of my wife and he couldn't keep her - she hadn't barked once while he was feeding her and he thought she couldn't bark, so I said let's call her "Aussie" after the Besenji; well, after she had her litter we had her spayed and I asked the vet what breed she was and he said, "Blue Heeler." She was apparently just going into "heat" when we brought her home and I just wasn't vigilant enough to overcome her wily ways.
And, the no-barking part was just a bit of fear, I guess, she barks the loudest and most strident of the three now, and strangers shake in their boots at the sound and sight of her full 33 pounds with the two baggy, boy dogs that go 70 pounds per standing next to her, tails wagging and mouths full of raggedy tennis balls.