Rude, intimidating step child
I have been with my bf for 7 yrs now, we have 2 children 1 from his previous relationship (10 yr old girl) and our own daughter who is 3.
I have brought my step daughter up like she is my own, I have always got along with her own business, and myself and the best share the same opinion with regards to discipline when the sd misbehaves.
Lately she has become rude, she is horrible to us all especially her little sister. She had us in tears last weekend due to her behavior towards our younger daughter.
I don't stand for her behavior and ask why she is acting like this, i tell her why she's upsetting people and that its not going to be tolerated. Only for her to come up to me and stand toe to toe with me smirking and giving me a nasty look, flicking her hair at me, I just told her quietly to go to her room and I walked away. I don't understand why she is doing this. She gets disciplined off us all and it makes no difference, her dad just think I'm too sensitive, but her BM goes mad hearing of her daughters behavior.
I bold over backwards for her at at one point looked after her more than her own parents due to work commitments.
Why this now, it feels like she is trying to intimidate me, she is rude, pushes me to my limit and laughs in my face.
How am I supposed to act and what am I to do ? I feel like I'm failing as a parent and step parent
(Excuse spelling i am dyslexic and also stressed out by this all)