I'm just throwing this out there.... unlikely but maybe worth a thought...?
Are you absolutely 100% sure she didn't have a false pregnancy? They will act pregnant and look pregnant, but "labor" stops when they discharge the built up fluid.
Found this article that refers to goats, but it can happen in sheep too.
http://www.liv.ac.uk/farm/species/goats.htm
"The most commonly affected are adults who have kidded several times, and may have been subject to artificial light manipulation of the breeding season, particularly in large dairy enterprises. The aetiology of this condition is still not well understood, but essentially is a build-up of clear fluid within the uterus in the presence of a persistent corpus luteum (CL) which secretes progesterone, but without a conception/pregnancy. The doe acts as if pregnant, with enlargement of the abdomen, udder development, and often milk production if not already milking. The false pregnancy can last for a variable length of time depending upon the initiating cause, but typically may last ~21days (ie 1 oestrus cycle) if the doe has had no contact with a billy, or at least ~150days (ie 1 gestational period) if it has followed early embryonic death. Following destruction of the CL the uterine fluid is released, hence the term “cloudburst”, and the doe will then often continue to milk for a lactation period. There is a high recurrence rate with ~40 % recurring in the following oestrous cycles of the current breeding season, and a 50% chance of recurrence beyond the current breeding season. Thankfully the condition can be readily diagnosed using ultrasonography, and treated successfully with medical therapy by a veterinary surgeon."
Whatever it is - I hope your ewe recovers!
