Aww Julie

It sounds like the other dog may have been fine until she got to your home and then began to establish her territory. Daisy and Molly both don't seem like the territorial types so they were afraid of her aggressive behavior. Their fear probably reinforced her feeling of dominance and her need to establish a heirarchy. That is my best guess.

I'm sorry that things didn't work out, but I'm mostly glad that none of the dogs were hurt, especially Molly or Daisy.

*hugs*