Maybe since it sounds like you have the upper hand (you can possibly force her to get rid of the dogs) you could get her to take the dogs to a trainer to break them of chicken killing. Tell her you would take a lower amount for compensation (price of replacement birds) if she lets you oversee her taking them to a trainer (and paying for it herself) who can break them of chicken eating. Otherwise you will be forced to ask her for the compensation of the birds as well as loss of eggs, meat, fertilizer they would have produced, feed costs, vet bills, ect. and to turn the complaint in to the authories if it ever happens again. It is on her to keep her dogs on her property, so if she needs to install a fence, that's her problem. All this about getting into your coop . . . welll, the darn things shouldn't be on your land in the first place and they have hours and hours while you are away to figure out how to get into it.
good luck. I realize you don't want to push her too far since she sounds pretty crazy, but if there is a trainer involved, they can maybe vouch for her mentality and maybe they will report her as an unfit owner, expecially if legal stuff has to follow.
