I'm not saying the OP's sister should not get a protection order. As long as she understands the order will not necessarily protect her from anything. The problem with protection orders, in most jurisdictions I'm aware of, is that the consequences for violating such an order are little more than a slap on the wrist. The defendant is usually released from custody the next day. There definitely should be stiffer consequences for violating those orders. I agree that the OP's sister needs a comprehensive security plan that involves the court, law enforcement, family and most importantly, her own instincts. Becoming proficient with a firearm, would be just one very important part of her overall security plan.
You are right on all counts, but what does that say abot judges and the laws? This is beyond the scope of the shotgun forum but judges that fail to use their powers to protect women, and in some cases men, from abuse should be shown the door.
As for the OP's sister's decision not to get a shotgun, she is probably better off. The one thing she does not want to do is take it out and then not be able to pull the trigger. I don't know about tasers but how about heavy duty pepper spray and a self defense course - something she may be steered into by a women's abuse counseloor.