Hi Karen. Swans know when there is something wrong with the eggs or the habitat itself. If there is a predator in the area, she may have been scared and left or possibly killed. She will protect herself before worrying about unhatched eggs. She may also have left to find her mate. Do you know where he may be located? If the eggs have been unattended for any length of time, especially after being laid, they are not going to survive nor will they be salvageable. You can leave them in the nest and let nature take its course, I.e. predator takes them, they rot or you can pitch them in the pond. They can explode and make a nasty smelling mess so do not place them in the trash especially indoors. The Regal Swan