She is one determined dog!! Somehow she needs to bond with her sheep so she WANTS to stay with them.
I can see why you are so frustrated, hard to keep a dog in if there is only hotwire and it is really expensive to put up permanent woven wire fence.
I blew 3 of the .5A fuses on the input side of my charger (it came with 2 spares). I don't know why they blow, doesn't seem to be related to anything specific. I've had the charger 3 years I think. Never knew it would be hard to find those fuses, none at the hardware store or the auto parts store. Of course Amazon had them.