It may be that she has sat so long on the nest that she has slightly sprained or strained the leg. As long as it does not look broken and she is still able to get up and down from the nest and in and out of the water, she probably needs to be monitored. If you take her to the veterinarian, she will lose the eggs and this is not something that you want to do unless you are absolutely certain that she is in distress and her life is threatened by not being able to enter or exit the water for feeding and preening.

As far as the environmental police, feeding a swan or other waterfowl bread as a treat once in a while is not going to kill the bird. Bread does not do anything nutritionally for the bird and can affect its blood chemistry, but is certainly not going to harm it as an occasional treat. However, lettuce, poultry layer pellets mixed with cracked corn would be better as they will add nutritional value as a treat or supplemental food. We hope this helps. Please let us know how she is doing. The Regal Swan