I am not sure if I said this in earlier posts, but I think the word "victim" has different meanings and contexts. There is "victim" in the sense of the Karpman Rescue Triangle, which represents roles that we play in a conflict dynamic, where we go back and forth from Victim to Persecutor to Rescuer:
His insight is that the roles are volatile, meaning that we tend to shift from one to another quickly. For example, I rescue my "non" husband by taking the kids when BPD mom is not available and he is working; I feel like and play the victim of this to try to get him to do this less and say no to her; when it does not change, I take a persecutor role, being mad at him and expressing it. Then I feel guilty and rescue, etc.
The way out of this is to be up front about what I want and ask for it, to take care of myself and do what I need to to be okay with where my wants are not granted, and to develop some way of making peace with what is. So there are clear means for dealing with my tendency to play a victim role when in a challenging dynamic.
This is distinct from actually BEING victimized. Being victimized tends to result in people playing that role in situations where one is not a victim, in my experience... but they are two different things. When someone harms a child, that kid is a victim, meaning that they lack power in a situation in which someone is harming them. BPD mom was victimized in a true way--she was physically beaten and locked in a closet and forced to be sexual with her mom's boyfriends. Now, she is an adult woman, who has power. She can leave if a man is harming her. She can say no if she wants. But it is comfortable for her to frame things as a victim, where we have the power. It is much harder to tell DH and I what she wants than to tell us we are bad and she is a victim to try to get us to do what she wants.
Being in a victim in fact, not as a role, is characterized by actual powerlessness, and actual abuse.
So in this scenario, as a stepmom walking into a family, there are ways I am actually a victim. I do not have power to alter the kids parenting plan or parenting arrangements, but if I am in this family, I am affected by this plan. I am powerless to make up for pain in the kids related to their mom. At times, I receive actual abuse--BPD mom threatening to harm me, the kids screaming at me it is my fault their mom is angry.
I do have some power--I could leave. It is important to acknowledge actual victimhood, because part of coming to peace is to recognize the ways I have no power, in fact, rather than chasing trying to cause change where I cannot.
Once I distinguish between actual victimhood and playing a victim role, it is easy also to see that the kids, and BPD mom, and DH, all have much more actual experiences of victimhood than I have... which helps me not to get attached to playing a victim role.
The "feeling" of being a victim--my anger at BPD mom for creating harm to her kids, for being irresponsible in ways that result in me wanting to take responsibility for things I really would not like to deal with, my anger at DH for not setting boundaries--all of these are ways I am affected by people's choices over which I have no control, but I am the one making the choice to do the things that feel unpleasant to me. I am doing that. These parts do not involve abuse of me. They do involve some abuse of the kids. But not of me. So playing a victim to coerce someone else just feels bad, and is less effective than just asking, receiving an answer, and when it is no, figuring out what I want to and can do about that.
There are real ways my BPD ex wife in law does victimize people around her. She hits, pinches, yells, says the meanest things she can think of, tries actively to get the kids to not like me, tells people they are bad and evil if they do not do what she wants, threatens to kill people, has tried to hit us with her car, lies to authorities about our behavior in a way that could have serious penalties if she is believed. That is abuse, and we are all the victims of abuse. But that is limited.