I think the fascinating part of this post for me is your sitting with Q on the stoop and what that says about your relationship.  Because you were able to understand that what she needed wasn't for you to jump in and protect her from her father, from the truth, from too much information, etc.  She just needed to bounce something off of you so that she could deal with it better on her own.  Which, if you think about it, is a really adult behavior (a healthy one at that).  She's doing that thing where she doesn't want to sit in Mom's lap and cry--she just wants to vocalize the new experience for her own reasons (which she may not understand herself).

I know that this happened thousands of times during the course of my upbringing, but I can't pull together any particular examples at the moment.  Thing is, Q probably won't remember those minutes on the stoop talking to you about the memorial service, once she's all big and independent.  But I'm willing to bet she'll always have this huge, vague sense that she can trust you, tell you what's going on in her mind without your freaking out or projecting your regrets and shoulda-woulda's on her.  She'll feel like you're her friend.  It's so hard to be a friend.  Nice work.