I purchased a pair 3 years ago. The first year the swams were 2 years old and she laid 7 eggs and would not sit on them. The last 2 years she did not lay any eggs. I am located in central Pennsylvania and have a 21/2 acre pond with a small island. She laid the 7 eggs on the island. Each year I take grass over to the island so she can use it to build a nest. Any information will be appreciated.