So my brother and his long time girlfriend broke up almost two years ago. They have two daughters, one 13, the other is 5. My brother has been dating a new girl for about 7 months and in that time my niece has been acting weird.

She once was studious and loved school, but now she’s been getting into fights and got in trouble for making out with multiple boys. She’s been swearing a lot more and has been outright rude to my brothers new girlfriend. BUT around her mom she acts like the perfect child again. As a family, we don’t like his new girlfriend, but we’re still nice to her because that’s what you do. But my niece continuously rolls her eyes at her or makes fun of her.

I’ve tried talking to her but she shuts me out and just goes on her phone. We were once close but now she only talks to whoever she’s texting.

Is it just her age or do you think that it’s her way of acting out? Maybe both? Advice?