A good % end up killing the child, since they can only have 1 child and hope for a boy.
This is true. In parts of country rural and have poor education there are family that will drown baby girl just to have another baby and hope it boy. If it girl again they drown again.
In this day and age I do not think it as important as before whether child boy or girl. Girl to can become very successful in society today. Maybe it harder in China but can move to western country where there less sexism.