Hi youcantfoolme. I am so sorry that your brother is so caught up in his own struggles. It must hurt immensely for both you and your mom. I feel bad for your brother as well. and your future niece or nephew. Everyone suffers and it is horrible.
You ask why it is taking so long to take baby steps. It is taking so long because your brother is afraid, desperate and is in an abusive relationship with someone who sounds like a high functioning, highly manipulative and damaged woman. Her behavior is being driven by the disorder and your brother is caught up in it.
Your questions are understandable. So is the hurt and the pain. The thing is, you are trying to make sense and find logic in something that is mostly unconscious and driven by raw emotion. Both your brother and SIL are caught up in this crazy dance.
Why would take her so long to get over things? To me, it's either you want to fix things or you don't. I know that's very black and white thinking but it's true. Why would it take months upon months of baby steps? I don't think my brother realizes how terribly confusing this is to us. We don't understand his wife and it's his job to bridge the gap between us.
It is taking this long because she is not capable of seeing outside of her own projections and fears. It is taking months and months for the baby steps, because each day more distance is added due to her disorder and your brothers inability/refusal to stop the dance with her. He is afraid and scared. I agree that your brother does not realize how confusing it is for you right now. The thing is, he is under an incredible amount of stress, fearful of his relationship, caught up in FOG, walking on eggshells and on top of that has to deal with all the usual stressors and now a baby on the way. It *is* his job to bridge the gap between you and your SIL, but he is out of his element and dealing with a totally abnormal situation. You can't apply normal rules and expectations here. Or you can, but it will only lead to more pain and frustration for you and will push him farther away. It may also make it harder for him to see the light and if he ever leaves her, it may make it harder for him to go back to you and your mother.
Maybe he does not understand because he can't right now... .he is overwhelmed and he may fear one more demand, one more stressor may break him. It sounds like he is being pulled in a million directions all at once. Again, your questions are normal and reasonable, but his relationship and he and his wife are not in a normal place. The same rules and expectations can not be applied without causing yourself more pain and anguish. Who knows what kind of behavior and abuse he is dealing with behind closed doors.
Your brother may come out of this okay. I hope he does. I also hope that when he does you will be able to repair the damage. I can tell you for sure, he is going to need a lot of support and a willingness to listen to him now and in the future. Do you think it is possible to put aside your questions for now and try to be that safe place of refuge for him?
My heart goes out to you and your mom. Keep posting here and talk out your hurt and frustration. In the meantime, have you read the articles here on radical acceptance? You may find some peace there as well.
Take good care.