As a mom of three kids close in age, I'm guessing you want an "easy" dog now. Herding is a controlled aggression, which is why so many herding dogs "nip" (or much, much worse). If you can't get the negative behaviors trained out of her pretty quickly, and commit to the regular exercise she will require to be a tired happy dog (I agree with the tired dog is a well behaved dog for sure) it may be best to find her a home where she can be the dog she was bred to be. My uncle had a Blue Heeler (which our whole family hated, because it bit everyone) and FINALLY gave it to a rancher after it bit a child in the face at a campground (while the mother was holding the child!!) The rancher then used this very intellegent dog to herd his cattle. The dog was a great fit for them and really loved his new life and "job."
There is no way I had the time or energy to cope with a dog who required training when I was pregnant with my third child and our old dog died (my other children were one and three at the time). I picked out a mellow 1 1/2 year old Rottie cross from the pound who was said to be "good with kids and cats, and housebroken." All that did prove to be true, and it was such a relief knowing that even if she never had a walk that day she wouldn't destroy property or harrass the children.
There is no way I had the time or energy to cope with a dog who required training when I was pregnant with my third child and our old dog died (my other children were one and three at the time). I picked out a mellow 1 1/2 year old Rottie cross from the pound who was said to be "good with kids and cats, and housebroken." All that did prove to be true, and it was such a relief knowing that even if she never had a walk that day she wouldn't destroy property or harrass the children.