why does dadima believe babita?

i dont understand why dadima believes babita when babita tells her that karan is miilee's boyfriend and not rahul!!

babita does convince dadima that rahul cant be miilee's boyfriend since he is engaged to nina and is soon going to get married to nina and then dadima agrees to babita- but doesnt dadima remember that nina came up to dadima herself and told her that rahul has broken the engagement with her and that she wants dadima to convince rahul to marry her but then dadima doesnt agree to force rahul!!

but in the episode it was like dadima had forgotten that rahul has broken the engagement with nina!!

i think she should have been thinking why rahul broke the engagement with nina? it could be possibly that he is miilee's boyfriend!! and she shouldnt be thinking that karan is miilee's boyfriend instead!!!

what do u guys think about this???