Sunaina will return to destroy Krishna's life because her son went to jail. She has planted Radhe and she paid the doctor big money to give this piece of news to Krishna (Fake Radhe is alive) . She feels that Krishna will immediately leave Veer alone and go back to Radhe.
She plans to destroy Krishna completely but Veer comes in between and doesn't let anyone come near Krishna. So, in the end all Sunaina's plans will fail miserably because Veer won't allow her plans to succeed..
This is the spoiler that is out... I don't know if it is true or false but, there is a possible chance of it being true because of the clear explanation of the Fake Radhe introduction.