Hi Regina,

The easiest thing to do is to reply “Yes, you are right” to whatever she says, and try to think about something else. For example, do not focus on her words, focus on the tone of voice and try to imgine a little child that begs for attention. She wants to play with her favourite toy: you, if you stay still like a robot long enough, that game will eventually be no longer fun. Use always the same set of answers “Oh sorry I forgot”, “Oh I’m absent-minded today I was thinking about something else”, “You are welcome to come at the family’s party”. Be boring, repetitive, lifeless and dead.
You’ve got everybody at your side, anything she may say about you to others will not affect them in any way. Feel safe.

If you want to help her break from that habit of her, after some training of the behavior above, you may start alternating between being kind when she is kind and ignoring her when she behaves bad.

When you are at home in private, teach your daugther you own values and how to defend herself against such aggressions. Sending your brother’s sister away from your daugther will not help her cope with other similar minded people she may find in life. What is someone starts acting like that at school? With such a training, your daughter will already know how to deal peacefully with the situation.