does brooke and julian have a boy and a girl or 2 twin boys

I can't answer that as I haven't seen seasons 7 to 9. But if you really want to know, watch the show.

I am really confused because they had 2 twin baby boys,but in the last episodes (SPOILER ALERT)there is a scene which takes place in a time when Jamie is Nathan's age at the beginning of the series and is about to play a basquetebol, basquete game.In this scene Brooke looks at her children,one girl and one boy.