I'm not in therapy right now. I found a good trauma therapist but can't afford the 2 hour drive and fees each week when I got a pay cut for the year.
I'd like to go back to that T. Thanks for asking. That was very considerate of you, Notsowild. :)
Getting back to the question "should one be angry..." yes, if a survivor is already angry and has stuffed it in order to preserve the abuser-abused relationship. Then, probably yes. As said above, it has to come back up and be processed along with the gradual adoption of a more adult and healthy self concept. Relationships are mirrors, and denial and repression to maintain the dysfunction requires a grief process, as stated above, to move away from that place. But, if one doesn't feel anger and if the bystander-mother was merely not aware at the time, and if there is no anger, Why should anyone say it must be there? It only takes an imagination to see that not everyone is the same. Most people need to get in touch with anger they've carried. Some never were angry and only are not because they are still children or still in denial. But, others may not need to feel anger to know what happened to them and who they truly are.
A mother-bystander is a mirror that reflects a warped image of oneself as a survivor. Anger is only one dimension of reaction to that image.
As someone who survived her mothering and lack thereof, I no longer find that image a true reflection. Anger is part of that dismissal. But after I accepted the anger and saw beyond it, there's still that small bit of me that knows I am not bound to look in the same cracked mirror forever. I see beyond it to a better me that I've held onto in faith, even if that person is a survivor with PTSD and issues. I have to believe in that person who never saw her reflection in that dirty, cracked mirror and was always there, keeping me going. That higher self has to integrate with the angry face in the cracked mirror until they become one. That is taking practice and time. The me that is still in hell has to merge with the me that is okay and peaceful, untouched. I am somewhere in the synthesis of these experiences and images of myself. I could be angry that my mother held a bad mirror up for me, or that she allowed my siblings and I to be hurt by our father and others. I am angry about that, and I think it's normal to go through that. But I don't feel stuck in it like quicksand. I get out and feel other things now. :) I somehow find myself back in anger, but I manage to move though it. I find better things to feel, too. It is synthesizing this that I'm now working on.
If the anger needs to come, it will come. If it doesn't, then don't go looking for it. Why judge someone for feeling or not feeling some emotion toward someone who was a bystander. There are 1,000 shades of involvement, tempered by love, human weakness, and forgiveness.