I grew up with 2 sisters and none of us felt like odd man out and there was no ganging up, just usual sibling arguements. I wouldent base on gender personally as no guarentee. I have a daughter and this ones a boy. I dont think they will miss out if we dont have more. If either want to do something paticularly in gender steriotype then they have me and their daddy just if daughter wants to do sports my dh loves them as we dont go for gender steriotypes. They will have friends as well. I didnt do makeup etc with my sisters. I know lots of people who grew up 1/3 and didnt feel ganging up went on. If you want 4 go for it. With degree your still young. My mum is finishing hers and turning 60 soon. She has done through open university