Leaving a house to your heirs. Do you need a Will in order to refrain from giving possesion to someone specifi

A friend of mine asked me what they need to do in order to distribute their possesions to their son when they p away. They do not want to leave their house to their daughter only their son. As far as I know, if she pes away and dies without a will (intestate) than her belongings are split 50/50 with her two children. However, I think if she has a Will that states leave the house to her son, than that is the only thing she will need to do. Does anyone know for sure what she will need to do to leave her house to her son so her daughter does not get a part in it. Thank you