She has given Veer the impression that if Dev mixes with Kaajjal then the same thing that happened to his first love will happen again.
On the other hand, when Ameesha is alone, she keeps repeating that if Dev and Kaajjal get togeher in love, then somehow Kaajjal will be able to save Dev from his ugly fate! That's why Dhruv needs to woo away Kaajjal.
I hope she gets so mixed up in these lies that eventually she tells the wrong story to the wrong person and exposes herself!