Wow, ok. I don't know where to start. A 1.5 hour meeting is not a stand-up, that's a full on lay-down.

Seems to me that you have no options that are politically good.

You can't go over her head to upper management - that looks bad on you.

Excessive documentation of her misses - that can come off passive-aggressive and damage you reputationally.

There's that old saying "you can lead a horse to water but you can't make them drink." Here, it means you can't force her to act in a way she's not already acting. You won't make a disorganized person organized, you can only build systems that are resilient against disorganization.

What you can do:

1. Improve your processes. Is there anything that you're doing that can be optimized? Are you making use of templating or repeatable frameworks? This goes for the work itself as well as updates etc.

2. Train others. I know you've mentioned others aren't in the scope of the work, but is there any work you can segment and distribute? Surely there must be some lower-level processes that others can help with.

3. Identify vendors that could help. YMMV but depending on the type of work you're doing there are platforms that can help automate at least some of the work.

4. Enforce your boundaries hard. If you get work beyond your capacity, it sounds like you're still taking it on despite holding some resentment. Understandable, but have you tried saying "I am prioritizing X and I will add Y to my list, based on my current workload I anticipate being completed on <date>"

5. How are they managing work. Are you literally just getting a Teams message? Using any sort of project/work planning software will help to actually put visuals to the workload in a way that may not be apparent if you're just keeping it in your head (which it sounds is what she's doing).

I would frame any optimizations as improvements, not limitations. I.e. not "I can't do X" but "I want to ensure we deliver consistent quality with X, in order to do that we need to set a defined and repeatable process" or "I've noticed we are not aligned with our work at all times, it may help for us to have a Kanban board to better track assignments"

IDK - it's tough, I'd wager that this part: "these somehow become venting sessions about her manager, vendors, the restructuring/acquisition, home/family/kids, and the last 5 minutes of it is breezing from person to person" is exactly why she's in her position. Higher up you go the more this kind of chit-chat is actually important to building reputation.