I do have a problem with the fact that she couldn't be bothered to come up and see him for the past year while he was literally dying. She has always lived with her mother.
Well... What I've learned is that having a spouse who is an alcoholic is a very different experience from having a parent who is an alcoholic. When I left AXH, the kids were relieved. And then they became angry. And then they veered in different direction and have expressed pretty much every emotion known to man and then some.
Having a parent who's an A is difficult. Often, you hate them for the abuse they've put you through -- yet you never stop hoping that they will turn around and express their love for you like a "normal" parent. You're pulled between those two extremes the entire time.
Some kids react by becoming uber-codies and waiting on their A parent hand and foot and hating the non-A parent for "abandoning" the A. They sort of step into the non-A parent's role. Some kids make a clean break and refuse to have anything to do with the A. Some kids are torn apart on the inside because they don't know how to stop wanting the love of a person they hate. And some kids react in other ways.
I think when you're talking about addiction, you have to drop all your expectation of
any relationship being "normal." I know that my "normal" friends who have never experienced alcoholism up close and personal have reacted in many different ways to my leaving my AXH -- some judge me for "abandoning" him; some think I'm exaggerating how bad it really was; some think it's really odd that I have no contact with him other than about kid logistics. And that's OK. Other people are on the outside of your relationship and don't know what it's like. Just like you are on the outside of the relationship between your AH and his daughter.
I know it's easy to judge. To think she doesn't love him. But you have to trust that she is able to know what she can handle as far as her AFather goes. You have to leave that to them.
About your AH: Going to see her sober is probably very frightening to him. It's probably much more within his comfort zone to stay home with you -- because you guys have hashed through what his drinking did to you, and to your relationship. He probably hasn't done that with his daughter. He's probably terrified of her bringing up past offenses and wondering how he'll handle that sober.
Just my five cents.
