very touching story aryan, its a lesson to children and also to parents.,  
 
I agree Niyati shouldnt have behaved like that, but her mother was also not right, she could have understand whats the problem wiith Niyathi, if she had given a little time to daughter, she could have easily solved niyati's problem, but the mother choosed to be strict, wanted her daughter to be systematic, 
She has to know, Lessons must be taught when the mind is peaceful not in such situations.., Poor little girl, totally worst day in her life.. not only had a fight with her friend, and also lost the valuable precious blessing of her life... her mother., 
A  request to parents ..dont try to be teachers or preachers all the time, choose the best time.. when it is to be done.., Help them, only when it is needed...