While they were watching Ann's date with Tom, Leslie says that she likes Italian men to Ben. In real life Adam Scott (who plays Ben Wyatt) is of Italian descent.
Leslie gives her mother a pillow with an embroidery of the event that happened on the day she was born - Joseph Stalin dying. This would put Marlene Knope's birthday as March 5, 1953. Pamela Reed, who plays Marlene, was born April 2, 1949.