I think it's wonderful of you to offer to help your neighbor build a run for her dog so she doesn't have to get rid of it. Yes, it's sad, hard, and frustrating to lose your birds in this way, but that is one of the hash realities of free ranging. Your chickens are at risk. Is the dog a known nuisance in the neighborhood? If not, I'd be more willing to help the neighbor, too. If it's a chronic problem, not so much. Anyway, I just wanted to commend you for being neighborly instead of vindictive. It can go a long way.