His mother favours his brother’s wife over his wife
Question

                My mother never prays, backbites and hates me because I confront here with islamic teachings.  I even took her for haj hoping Inshah  Allah she will follow the right path.   
Now she is more attached to my younger brother and after his marriage she supports his wife all the way.  My wife being quietly obeys  her and does all the household chores.  My mother even used to curse me.Should I be strict with her or will this be against the teachings of Islam.
Praise be to Allah.Whatever 
          wrongs your mother does towards you, you have to bear it and be patient. 
          Indeed, you have to take advantage of her still being alive, to take 
          care of her, because there is a great reward in that. One of the salaf 
          wept when one of his parents died, and said, “I used to have two doors 
          to Paradise; now one of them has closed.” And the Prophet  
          (peace and blessings of Allaah be upon him) said: “May his nose be rubbed 
          in the dust (may he be humiliated), whose parents, or one of them, reach 
          old age during his lifetime, then he is not forgiven.” It is difficult 
          for parents to control their emotions, and it often happens that parents 
          are more inclined towards some of their children than others. We have 
          to put up with that and bear it with patience. Soon enough we – if we 
          live a long life – will be in the same position. 
 Shaykh 
          Muhammad al-Duwaysh 
 If 
          your mother persists in not praying, then you have to persist in calling 
          her, with gentleness and kindness, and keep on praying for her to be 
          guided by Allaah.   
The 
          one who neglects to pray altogether is a kaafir, but parents are accorded 
          special treatment even if they are kaafirs, because Allaah says: 
“But 
          if they (both) strive with you to make you join in worship with Me others 
          that of which you have no knowledge, then obey them not; but behave 
          with them in the world kindly” [Luqmaan 
          31:15]