it happend how it is and was in normal way. the son got the farm of his father - how it looks like. and clear that his mother went to her 2nd husband´s house - her new home. the son has the right for his fathers farm, not the widow. if she would have not married again she would have most time housing law. in present days WITHOUT a testament children (illegitim and legitim!) get 2/3 and widow 1/3.
she would only get house if no other children and her son would die before her.
if husband makes testament that widow gets the house, children will inherit AFTER her death the house.