Anne is already pregnant at Christmas time. The baby comes well after Father's Day (June), probably July or even later and there is no attempt to make her look pregnant - not even maternity-type clothes. She continues wearing skirts and tucked-in blouses, remaining thin through the entire picture. She's even wheeled into the Delivery Room with her stomach looking as flat as a board.
Longest pregnancy ever. Ann is known to be already pregnant in April (when Felix puts his coat on her and mentions it's April). Shortly after that, Adam mentions it was Father's Day "last week." Months later, when Felix leaves, the telegram they send to Felix is dated June 11. When Clinton comes out after Ann has delivered, he mentions that Ann is fine but it's always hard when "it's a pre-mature baby" indicating that the baby wasn't due for a while.