She shows symptoms of possible poisoning....very like Mareks symptoms....do you have any plants in your garden i.e. foxgloves, lupins...? .she may have eaten something toxic..mouldy food..which she may have found while she has been foraging around in your garden...you are lucky insofar as you have access to epsom salts....you can give her some which should flush out any toxins..one teaspoon per ounce of water...