How to cheer up my disappointed wife?

well she is pregnant and we just found out the of our baby. we are having another boy!!!!! when the doctor told us i was like yes!!! but my wife was a bit disappointed. we have two sons already so she was really hoping that this baby would be a girl i mean she was really set on having a girl this time. when the doctor told us she sighed and said ok. she has been pouting and mopey all day. how do i cheer her up?