Whether you get a male or female is random, but for some reason I also tend to get more boys than girls. On my V1 I didn't get a girl until my sixth generation. After a while a pattern began to emerge, though. Give it one or two more generations and you should get a girl. There's really no particular reason you get more boys than girls.
The gender you get on your Tamagotchi is random. So far, I haven't been bewitched with rows of generations of males nor females with my three Tamas running. People used to say there were different methods of getting boys or girls for your Tamagotchi, but all these had been proven not true so far.