this reason is totally nonsense. Then she should've tried to kill nehmat again becoz now also rupi loves nehmat more than naaz
I do understand the meaning of want and need.
As a young girl, Jasmine wanted to destroy Fatejo just to satisfy her ego. But later with Naaz, her requirements changed.
Jasmine came back to India with Naaz with much expectations. She thought that her father would forgive her and allow her to live with them. However, Rupy did not accept her and wanted Jasmine to move to another city. So finally Jasmine realised that she cannot fulfill Naaz's wishes. Hence, Jasmine left Moga and requested Tejo to accept her daughter as her own. Yet things didn't work out according to her plan. Naaz (learnt that Nehmat is her half sibling) started getting jealous seeing Fatejo with Nehmat. Jasmine understood that Naaz would never be happy with Fatejo. Also, she knew that until Fatejo is alive Naaz will never get the love she desires from Sandhu's (even today Rupy loves Nehmat more than Naaz). Therefore, Jasmine used Shamsher to kill Fatejo and Virk's. Nehmat would have also died during the accident but Naaz saved her.
The need to kill Fatejo arised due to Naaz.