Friendly Mallard Duck Chilled near us until this Happened

As we sat on a bench by the lake, a female mallard duck caught our attention as she swam from across the lake and headed directly towards us. She came to shore near us and stayed awhile hardly noticing us. After a while, I quacked at her and she soon swam away. Surprisingly, she swam back shortly after to a spot close to us. She continued to stay there for a long time and was still there when we left.