I am a 'wizard'. I can help you guys to predict you will have son or daughter.
Rule 1: a tough manly guy and a tender woman.
Result: always boys
Rule 2: a mild and weak guy and a strong-charactered woman
Result: always girls
Sample: twin girls of actress, Julia Roberts
Personalities of this kind of woman: ambitious, controlling, hysteric, strong sex desire
Rule 3: almost equal ability
Result: sometimes boys or girls. It is up to the comparative ability at the time.
Rule Four: exception: In Rule one, if you get girl, she will be a tomboy. In rule two, if you get boy, he will be a female boy.
we need to compare in sex ability, body condition, personality.
It is my long-termed observation.
Look at yourself if your are a guy.
If you have no sister and you only have brother, your mother is patient and mild, in addition, your father is a real man who is brave and manly.