My father took my mother's gold and brass possessions, added another sum of money, and purchased a plot of land which he registered in her name. He then built a house on this plot from his own money. At the time of registration, he was married to another woman and had a 4-month-old daughter apart from two sons from my mother. He later had three sons from his other wife and a daughter from my mother. The total number of children from his first wife is three, two boys and a girl, and four from his second wife, three boys and a girl. Please note that his second wife did not contribute anything towards the price of the land. My question is: since my father wants to sell the house and give everyone their rightful share, how is this to be divided according to Islamic law? 

It is impermissible for the inquirer's father to force his wife—the inquirer's mother—to sell any portion of the land registered in her name. She is not obligated to do so and this does not involve any injustice towards the second wife or towards her children.

The father is free to dispose of his possessions in the way he sees fit and in the manner that helps those among his family who are in need. Otherwise, he may leave his possessions as a legal inheritance to be distributed proportionally as prescribed by Islamic law.