Is there a difference between a new born baby overalls?

Me and my girlfriend were shopping at target for our unborn child. We still dont know what the sex of the baby is but we are both really excited and we wanted to buy the baby something. Well i am a huge fan of overalls and my girlfriend said we couldnt get them because boys and girls overalls are diffederent. So i lucked out, but something tells me she wrong. Please help :o)