Was it just out of anger/ego or she really thought that Saadhna can not give her a waaris and Raagini can, so next time Saadhna does not spoil it all. Remember she said Sadi is jealous of you cause you have Ranvir ka pyaar and a baby on its way that she doesn't have. Does she believe that Sadi can not give her baby and also that Aalekh does not love her? Now that Aalekh is getting normal, can Sadi not have a baby in her Pov?