Support in helping my Dad/brother moving forward

I've lurked in this community and posted several years in the past. My mother is my Q, and the full story can be found in the below posts.

Q has decided drinking is more important than the birth of my first child

7 years of aan alcoholic mother- thought I was in a good place unitl recently

Q is a monster after breaking 15 month sobriety

TL;DR for backstory: My mother is my Q, and has been an opiate addict and alcoholic for 10+ years. She's been through a ton in that time frame, including countless ER/hospital visits, surgeries, arguments, major life events missed, etc. I've done everything in my power to support her, from positivity, to tough love, going to CR with her, attending Al Anon, I started therapy in 2019, etc.

Where we are now- I was at a destination wedding in Cancun this past weekend and my wife was acting weird. After much prodding, she disclosed to me that my mom had fallen after ODing on muscle relaxers and broke her neck. She is still recovering from a major back surgery, so this was especially worrisome. I lost it at the wedding- I was mad at my mom, mad at my Dad/brother/wife for trying to hide it from me, and deeply saddened.

After sobering up and talking, I completely understood my families position in just tyring to keep it from me until I got home, so as not to ruin another vacation (this has happened at least 5 times while I've been on some sort of vacation in the past).

I sat down and spoke at length with my Dad, brother, wife, and Grandma (Dad's mom). My Dad had said after the last relapse, that we would be 100% done if it happened again. She has not made any effort to help herself, attend AA, go to Church, seek therapy, or anything that would help her overcome this. Well, since it happened again, while my Dad and Grandma were up at my house caring for my son while we were away, he said he intended to stick to his boundary. That, after 10+ years of enduring this and trying everything to help support her to overcome this, he cannot do it anymore. We talked about next steps- he has already rented a storage unit to move his stuff out of their house. He has set up an appointment to meet with divorce lawyers (he had previously met with them but ended up stopping to give her another chance in the past). He intends to file for divorce, put the house up for sale, split the house money with her, and move into a place of his own.

This would have devastated me previously, but I've been mourning the loss of my mother for years and years now. Now, I am honestly a little relieved to maybe have some normalcy in our family once again.

My question, though, is how to support them through this process. I told them both they absolutely must seek out therapy immediately- I struggled hard with my mother for years, until i finally sought out therapy, which has helped me tremendously since I started in 2019. I told them I would be more than happy to help with the process, but ultimately it is up to them to get it set up and scheduled.

My mom had always wanted us to "hide" her addiction, as she was embarassed and ashamed of it. She said it was "her story to share", so we never made it public. I'm not a big social media person, but I finally made a lengthy post on Facebook about her addiction, our struggles, etc. In the post, I said that I wasn't makign the post to vindicate or hurt my mother, but rather to share my truth and my story, and to be honest about it. Lies are the cornerstone of addiction, so I felt like honesty was important here. I also said I wanted to share to hopefully reach anyone who struggles with something similar. The response has been overwhelming, and we've received all kinds of support from friends and family. I feel like that will be very important moving forward.

But I know nothing about divorce or how it will go. I know my mother will fight it once she gets out of the hospital. I live 5.5 hours away, so being physically present will be tough but am already planning to be down there when I can and have discussed with my boss. I am trying to figure out how to be supportive to them during this time. And experiences/advice is appreciated.