Niece who is 6 has a friend who is sometimes really sweet, occasionally gives her small gifts. My sister doesn't reciprocate as she doesn't want to encourage this but would get friend a nicer gift.
However, there was an incident recently whereby this friend told my niece that when they are older she would kill her, this was after a small tiff - niece was playing with other kids. TA overheard and sent them to teacher.
Niece told teacher what had been said, friend denied this and we are guessing they put in a consequence. They use the card system. Friend then asked niece why she had told the staff. Friend got very upset and niece is quite sensitive. Previously friend said to niece if you don't play (whatever game they were playing) my way I won't invite you to my party and the whole class will be talking about it.
Sister found out all this from niece, I think she should speak with the class teacher so she watches the friendship. She is reluctant to be "that mum". Im worried that it's all a bit vindictive for that age. Am I overreacting?