1 rishi cannot be the love of her life coz when she picks up the gun he is standing behind her holding her hand. No man who loves his wife would do that. Neha has no problems in shooting kabir for rishi but even in her dream she knows rishi wont face the world for her.
2 the look she has when she shoots kabir is more like revenge not for her husband but for herself.
Probably the dream sequence is as she has no problems shooting kabir coz she believes he was the one who planned to kill her.
Your take on the dream?