You are very welcome. We are sorry that we could not have been more assistance. If she had a cough, she could have contracted pneumonia, avian flu or some type of fungal infection. In any case, getting too cold and not being able to stay warm or dry, can certainly end a bird's life. If there is any consolation, at least you know what became of her and now can focus on ensuring the male a safe and happy life. He will get along just fine without a mate and will provide you with many hours of enjoyment. The Regal Swan