Fatima, I think that Aarushi is not able to forget all the miseries & sufferings caused by Krishna directly or indirectly to Prats & her family. So this hatred in her heart for him is not making her to see some positive things in Krishna ..........................
When somebody hate some one that that hatred overshadows all the other things.......................moreover Krishna is responsible for getting a gundi bhabhi (Komal) in the saxena family, hence Adarsh decides unwillingly to marry Komal........She is not able to digest all these things............so her hatred is forcing her to blurt out all those bad thing to Krishna............
wow i feel like tht you are saying all this from your heart are u okiee