If we want the serial to continue for sometime... so we need story to move forward.... so kuch na kuch to dikhayengay naa....
and even in our real lives we change according to the situations.. we can get angry on very small issues... so Narmada is justified with her anger (ANGER).. i am not in favour of Narmada slapping Imlie... but still she can get angry on her, scold her, upset with her... Aru is Narmada's life line.. and if something happens to him she will eventually be very upset... Narmada tried to stop Imlie from going out that particular day only she she never stopped her from doing anything so it is easier for Anyone to instigate Narmada against Imlie...
Rant Over...