How Can I Help a Friend That Has Left Her Abusive Husband?

I would be careful yourself.
Because, the Ex knows probably, who her friends are.
What if he contacts you for information about her?
Your "job" as a friend, is to keep her information and life, confidential and private. That is how you can help her.
Or she will be in danger.
Just look out for her.

And if her Ex is going to lose his job and license... then he will hit another rock bottom... and he may get even more volatile.
So look out... all of you, for that.
Be safe. For yourself and for her.

If you notice anything about him or what he is up to, alert her or the police.

Make sure he is not following you or anyone that is associated with her.
Because, he will probably... want to find out where she is. Somehow. And he is volatile and not in his right mind.

If your friend needs money and you can help her, then I would help her.

Tell her she probably needs a P.O. Box to get her mail etc.
And so that her Ex cannot learn of her street address etc.

She has to stay in hiding. And who knows for how long.
Her Ex sounds like a ticking time bomb.

And, she needs to alert the school that her kids attend. Because what if he tries to kidnap them? (if she has kids that are in school).

I assume, the women's shelter or whoever is helping her, has given her a lot of information and resources to help her.

Wow. My previous answer was that it sounded like he was on drugs (as my estranged spouse was), but if it is long standing, he may just be an abusive person (or a long time drug user). I am so glad she found the courage to get out. It is so much harder than most people realize. It is not just logical to people who have lived it. It usually starts slow and involves lowering the abused persons self esteem to the point that they are depressed and confused and cant think straight, or they think they can fix it if he would just...
I would say that helping her, if you want to help financially, could be done with a gift cert. to a grocery store or somewhere like alice.com, but mostly encouragment and support are the best. Let her know that you think she is brave (she is), that she did the right thing and you understand how hard it must be (it is). Offer to meet her for lunch or any outing. Tell her that if she needs you, even if she just needs to vent or talk that she can call any time. (if you do mean ANY time, be specific and tell her," Hey, even if it is 1am, and you need a shoulder, I am here- but only if you can and mean it).
Dont judge. Ask if it is okay to question her about what happened- she may not be ready to give full disclosure. Just keep telling her that you are there. Some times we need to be reminded and sometimes we need to know that someone is still, really, there. Even if it has been weeks, months, years.
God bless you for caring for your friend so much. She needs more like you.

Everyone has already responded with good advice about safety for her, the kids, and for you as well as her friend. I'd add that she probably needs A LOT of encouragement that she's doing the right thing and that she can get through it! Then, she needs the practical help starting over - this would be a huge, daunting task coming out of an abusive situation. She needs to take care of her basic needs first - safety, then find a place to live, furnish it, prepare for a job search, find a job, make sure her children are taken care of, then trying to recreate some level of normalcy for her family. Her assets could be held up in messy divorce proceedings, making it all the more difficult for her to take care of herself. I would assume that everything from the basics of money, gift cards, clothes, babysitting time, outings for her children, even a new routine - a homecooked meal & movie night once a week. These would all be really helpful for someone having to rebuild her life from scratch!

I'm surprised... I really didn't think what he did was that bad. Of course, I don't know other details, or if here is more history here.

I've been in a marriage with a few moments like you described and we worked through it very quickly with professional counseling, and have been happily married for 10 years. I hope all works out!

Laura S. said exactly what I was going to say. It is common for women to stay in abusive situations partly because they feel they have no resources, no way to do everything on their own. Welfare won't cover all the costs of rebuilding. Help her get resources. And help her have some regular time to herself and regular fun time with friends. What a good friend you are!

She needs a lot of support and encouragement right now. It is always good when women get away, but it is a long road ahead. In fact, abusers become MORE manipulative and abusive as they are losing control at this point. My friend is going on a year and a half with her divorce. I know another woman who is going on 2 years of triyng to fight the courts to ensure her safety is protected and the man is held accountable for his actions. So while she's "left" she has not really even begun to have to process this and move on and has a long ugly road ahead of her.

Just let her know you are there no matter what. I had a friend that was in a similar situation not quite as bad. He would never have hurt the kids but was willing to hurt her usually when he drank and then didn't remember it. She had to get the cops to remove him as well and then she went to the ER cause she passed out. I kept her kids for all of last school year two nights a week because of her work schedule. Thank goodness she found someone else this year that could come to her house and help her cause I couldn't do it much longer. I kept three out of her four kids. But I just made sure she knew I was there.