I'm so sorry WeHave. That's going to be tough for your partner. I know. One thing that was huge for me going through something similar was when the people who cared about me just let me be me. I had a lot on my plate so it was good when my friends helped me when they could but also let me get what I needed to get done done. The last thing I needed was feeling guilty about not being a good friend when the truth was sometimes I just had to suck it up and be strong for someone else. I hope your partner let's people help her. She will need it even if she feels she doesn't.
One thing I learned was what a help it was when someone just did something I needed without me even asking. This may not apply to your situation but as I look back I see that when someone close to me just took care of the smallest thing I needed without me asking it was huge! Like if I needed a truck to move something for my parents. Instead of me asking a bunch of people can I borrow a truck, I had a friend who knew I needed a truck to get my mom's dresser moved from her room to my house. She just went and got one and then said she and her boyfriend were picking it up and bringing it over. What time do you want it? Lots of people ask if you need anything when times are tough but when someone just sees something and gets it done for you it's huge. I had so many decisions to make on some days I would get where I couldn't decide which socks to wear. I now know why people bring food to someone during these times. The simple act of cooking and eating can be overwhelming. If I have a friend going through something like this I will just clean their cats litter box for them, pick up their dry cleaning, or bring them some groceries just because I know what it is like to need help, not know how to ask for it, or think I can just do it all even when I can't. I would ask what do you need and not wait for them to tell me what they need, how to do it, or when to do it. I would just say consider it done. Now go do the important things up you need to do. Helping someone do the simple things so they can focus on the important things is a big deal when you have big things to worry about.
Just what I learned. May not apply to you and your partner like I said. Regardless, I'm so sorry about her Dad. I'm glad you aren't drinking so you can be there for her. I'm glad she is getting help. It ain't easy watching someone you care about have a hard time. I care about you too. (((Hug)))