@ThousandsOfTulips
So you're hoping to bring a baby into this mix as well?
Children behave "badly" when they are struggling with something. It's natural for her to be distressed by the family breakup. What support has she had to process this and come to terms with it? It can be quite traumatising for a child. To then have her father living with another woman he has only known for two years, in a place which is meant to be her home as well, adds to that distress so it's hardly surprising she is not behaving as you would ideally like.
The idea of adding a baby into this situation any time in the next few years is bonkers and, frankly, utterly selfish. If you decide to stay then you need to accept that your step daughter is a child and you also need to prioritise her needs. You chose this situation, she did not. She clearly already feels displaced and insecure. She's had to deal with so much change and needs a period of stability. A half-sibling who (as babies do!) demands a lot of attention and also gets to see her Dad every day and isn't shunted between homes is hardly going to help, is it? And given how you speak about her, it's pretty obvious that even if you tried not to, you would treat a baby of your own very differently. What you are apparently planning will be so, so damaging to this little girl. Do not do it, please.
Does she get regular quality time with her father without you there?
"Children behave "badly" when they are struggling with something. It's natural for her to be distressed by the family breakup".
Ok. Firstly I have two sons and I am a widow. THAT is traumatic for a child, never seeing their Father again, but do you know what, my two sons are not and never want to be labeled as victims. It is not traumatising to have 50/50 custody and still have the privilege of both parents love and support. The 9 year old would have quite quickly worked out that Daddy 'feels' guilty and she is more than likely taking advantage of that other than 'feeling traumatised'.
"What you are apparently planning will be so, so damaging to this little girl. Do not do it, please."
The audacity of this sentence is quite astounding to be honest. The OP has every single God damn right to have a child whenever she wants. Her decision should she choose to have a baby has absolutely nothing to do with the SC. She is nine.
"A half-sibling who (as babies do!) demands a lot of attention..."
So following your logic, perhaps all parents should only ever have one child so that the eldest never has to share attention with any siblings (half or otherwise).
And lastly who on earth are you to tell the OP that she is selfish. The child is acting out because she is allowed to do so. Children will only do what they think they can get away with, until someone steps up and becomes her parent. The OP can't, her hands are utterly tied. She cannot care more than the parents do and she is certainly not there to pick up the slack.
"And given how you speak about her, it's pretty obvious that even if you tried not to, you would treat a baby of your own very differently".
Two things here, firstly she is asking for advice on how to deal with a child who finds it acceptable to shove her around and be rude. How about helping instead of knocking her down and telling her how unreasonable she is for wanting a child of her own. It's something that you have so why is she afforded the same courtesy?
Secondly, yes she will treat her own child very differently because it will be her child. She will have more rights and more of a say into how her baby is brought up.
The ONLY thing that I agree with you here is that the daughter does need some time with her Father alone. Not all of it as the daughter does have to understand that her Dad is in a relationship with another woman and if Dad took the time to talk to his daughter, to make her feel secure than half of these problems would probably disappear quite quickly.
Can we please stop labeling these children as victims. Who on earth wants to go through life being one of those? Can we not ask these parents to just start talking to their children and can we please please please stop blaming stepmothers for every single little thing. I am so tired of seeing the same old "the children must come first" sentence. It is nothing more than virtue signaling.