It is obvious that the current situation of Tara's will end with her getting a child.
Do you think Urvashi wants Tara to adopt her child, for the money? Is that why she is instigating Tara and bringing her inability to bear a child to the forefront.. maybe when Tara is completely distressed, she will say for Tara's sake, I will give my child to her..and Saloni will get to reveal Urvashi's motives..
Just wild imagination.. but you can never tell with the soaps.. anything is possible.