BPDFamily.com

After months in therapy trying to address all the conditions that have been projected on him (ADHD, depression, anxiety, malignant narcissism...) my son's therapist has concluded he is actually doing very well and his wife likely has BPD.  Her "mood swings"  have turned violent. Yes, she is now physically abusing my son.  His efforts to get her help "have forced" her to divorce him.  He is now a villain, and by extension I am too.  This is such a sad and insidious disease.  My heart is breaking because what I have read indicates how much pain she must have to put  her in 24/7 survival mode.  At this point my greater fear is for my son and their infant daughter.   
I also feel very guilty for telling my son to ignore some of her hurtful and destructive behavior because the hormones of Pregnancy and post partum make it  difficult for some women.   
Reading the forums, I know we are not alone and I am here looking for insight to guide my granddaughter through what is to come.

Does she also show strong entitlement, narcissistic traits?

I am slowly coming to terms with the fact that BPD can be managed much easier than narcissism. In the latter, change is almost impossible and they will erode everyone around them, they don't realize the pain they are causing, or worst they get a thrill out of it because it gives them a sense of power, an exit to their powerlessness. In the former, I think they do have a sense that they are doing damages and all hope is not lost ...

I find most people ending on here though are dealing with someone that is both BPD and entitled, which is a very bad mix in a parent.

I think, as a grandparent, you will have to be especially aware and cautious as to what is going on, and listen to your granddaughter, possible take her out of her mother's house at some point if the abuse is too much.

Thinking back on my own childhood .. how I wished my father would have kept me with him full time .. every children need a mother, but not an abusive mother. That's me though, and to be fair, I am in a period of intense rage right now because I am just realizing the extent of the pain my BPD/NPD mother caused me as a child ...

A child cannot protect herself in the event of abuse, an adult must step in.

You can offer love, a safe area where your granddaughter can talk, but truthfully, depending on the damages at home, she might just stop talking too. So... My main advice would be : be very attentive to any change in your granddaughter that might be caused by abuse.

PwBPD might be ill, but some try to improve and seek help and therapy. If your daughter in law won't even try, even for the sake of her daughter, chances are she is also strongly entitled/narcissistic possibly. Be cautious of narcissists...

How is your son doing?

What happened that was violent, if you feel comfortable sharing.

My son is now in the midst of a divorce and striving for at least 50 % custody.
Regarding violence...
She has knocked him to the ground, repeatedly kicking him, she hits him with an open hand if he is holding their daughter and threatened to close her fist and kill him next time. 
She has called the police to report that he harasses her and frequently accuses him of being a drunk (usually after she returns home after a night at the bars with her friends). 
Their therapist called DCFS on her but she is an extremely convincing actress and so the visit was inconclusive.
My only hope is that with narcissistic tendencies she views her baby as an extension of herself and will not cause her harm.   

Yes she is very entitled, her parents have stated they found it easier to either leave her alone or to just give her what she wants.   Of course they never mentioned any of these potential "issues / behaviors"  before the wedding.
 They dated a year which was clearly
a time when my son was being idolized  and the split  was unexpected and shocking.

This might come off as brutal, but extension or not, if she is already violent, there is a very real risk of abuse. And sometimes, it is not visible.

My BPD mother once pulled out a teeth that was not ready to fall. Put a tiny cord around it, made me sit, and tugged on it multiple times until it got out. To everyone, I had just lost a tooth.  It wasn't a huge pain, although it did hurt. She wasn't beating me with a stick, she didn't punch me. But she made me sit there with no right to move or cry. I was scared, terrorized and I had to suck it up. Most times, she would shake me violently.

With or without physical abuse, the screaming of a BPD, the rages, are themselves intense for a young kid to deal with.

Especially since they are separated... It might be a trigger for her, every time she leaves, every time she comes back. My mother was jealous of my love for my dad, triangulated me against him, almost broke my relationship with him. She would hurt me to get to him. I was too much like him, she would say, and then ignore me for days on end.

She was an alcoholic too. Alcoholism makes BPD symptoms worst.

Abuse is not only physical... Children have no way to defend themselves. A raging grown up is very scary when you are young.

I really wish my father had stepped up and gotten full custody. 50% is better than nothing... But if you see any signs of abuse, any signs of your granddaughter starting to look withdrawm... Step up. For her. For you. Too often, people close their eyes on child abuse. It is wrong. Sometimes it doesn't work, sometimes the law will refuse to side with you. But at least you will be able to say you have tried...

Sorry if I am painting a grim picture. But if she is already violent, then it is grim...  

If your son is receptive to support from you, I recommend Bill Eddy's book Splitting: Protecting Yourself While Divorcing a BPD/NPD Spouse. It will help prepare your son for the specific challenges of engaging the legal system while divorcing someone with a personality disorder.

Eddy has another book called Don't Alienate the Kid: Raising Emotionally Resilient Children When a Parent Has a PD.

Parental alienation is very specific to a parent with a personality disorder and is considered by experts like Dr. Craig Childress to be child abuse. If your DIL sees her baby as an extension of herself, and dad is split black, then it will be intolerable for the child to have a loving relationship because the child cannot have a separate self from mom.

Practicing the skills that Eddy and others recommend will go a long way. You'll have to learn to validate feelings because your grandchild will have one parent who cannot tolerate individuation without experiencing a threat to self.

Another book worth reading is Divorce Poison by Richard Warshak. Some of the examples can be extreme and your DIL will probably not engage in all of these behaviors, but it's good to be aware of them. And Warshak offers explicit tactics that can help counteract some of the disordered behaviors -- it's essential to learn this from others because many of the insights are not intuitive and must be learned.

There is also a board here on this site for divorcing parents that might be helpful for your son if he is inclined.