I’m a bit ambivalent about this one. On the one hand, I’m not really one for ceremonies and, in fact, the whole point of a funeral isn’t about honoring the dead, per se, as much as it is about helping those left behind with their grieving process which usually leads to it, but I’d say it’s more important to fulfill the needs for grief than specifically honoring the person, whatever that means.
Further, there comes the question of what exactly is needed for someone to grieve. If someone was a genuinely good and well-liked person, then people will pretty much only have good things to say about them. Hell, even if they’re pretty average, death has a way of helping us forget a lot of the bad stuff. But what if someone was just rotten to the core or if someone who really needs to be there, like a child or sibling, had a very rough relationship with that person. Should that person who maybe feels the need to air things out not do so for the sake of others? Or in this case here, the question is whether or not her need to be honest outweighs the grief of her family. That’s a tough call.
On the other hand, since it is clear that she wants to honor him, I’m not really sure exactly what that means. For some people, religious or atheist, that is something that is integral to who they are. For instance, my dad is very religious, attends church multiple times a week, it would be remiss of anyone giving a eulogy not to mention that. But for me, though I am a theist, I’m not defined by my theistic beliefs; in fact, other than the few people I’ve really gone into depth with on it, I’m not sure anyone else would be in the right place to say anything about it. Similarly, I’ve known atheists on both sides, some who are defined by that, and some who you really wouldn’t know either way.
So, the question she should ask herself is, really, how important is his atheism to who he was? From the story, that he’d even repudiate a chaplain, it sounds like it may have been something that was part of defining who he was.
So, with all that consideration, particularly given that she’d been largely disowned by her family anyway, she deserves to do what she needs to do to be at peace with his death and help her grieving. Further, though it would probably upset her family, I don’t think it’s a particularly healthy way to grieve by pretending that someone was something he wasn’t. And, I’d think it would even help her stay clean more, by being straight with the one person that was helping her, than forsaking that one connection for the hope of reconnecting with the rest of the family. If that connection was enough to make her go to that meeting and write the new eulogy, then it’s probably the one most worth cherishing and honoring.