Amrit has superiority complex, she thinks she is best in everything and everyone is below her,specially Nimrit... she was confident that she had Agam under her control before marriage and was looking forward to enjoying his wealth(aish aur aaraam)... It hurt her ego when Nimrit was choosen instead of herself on her wedding day and she is out to destroy the one who has disrupt her best laid plans...
Her attitude is like "this toy is mine, i will play with it as long as i wish and when i get bored of it, i will throw it but no one else is supposed to have it"
You would never hurt the person you love and the way she is creating troubles for Agam shows she dsnt care about him she just wants to win..
Woh Agam ko haasil karna chahti hai, like he is a trophy or something..