And it's in bloom! Excellent full plant!
I wouldn't prune it right now, unless you absolutely can't wait...the blooms are so thick, though.
For the time being, I'd just slip a stone or two on the right side of the trunk (in the pic) for
support, since I assume that's the way she wants to lean.

Great plant.

Josh

That's a great looking plant!

Here's how I approach it, for when you do prune. Agreed, doing it while it's flowering is kind of a waste, you'd likely trim a lot of them off... unless the flowers aren't that exciting to you.

Remove any branches that don't belong, put simply. Go for balance and a natural, tree-like shape of the branches, try to see just the branches, not the leaves. Keep turning it often as you work to avoid exacerbating the lop-sided issue, and to confirm before you cut, how it will look from several angles. Look from above, as well as head-on. Anything crowding the center, then going in a wrong direction should be removed first, IMO. Then you can see what needs to be done to what is left.

It's hard to be more specific from one pic. Showing a view from the top would give a better feel for it, if you're so inclined/wanting more specific directions. I don't know that it would be necessary to remove much from this plant to balance it out. Possibly leaning it gently the other way (it's tilting to the right, the trunk could repositioned to an even "V" and that would remove a lot of the unevenness,) and propping it, as mentioned until it "sets" in the corrected position, would make it look just fine.

I'm very new to this plant but have been trimming things for a long time, and for this plant - guiding its' shape as it grew very fast this summer, often removing little branches I didn't want the plant to waste energy on, a couple for evenness, and I've removed particular leaves in spots to see if that will inspire new branches at those nodes.

Are you going to try to propagate what you remove? The little branches I cut off grow well/easily/quickly, and there are a gazillion pics and testimonials out there from people who grew new plants from single leaves. That's fun!

Thanks for the advice, I'll hold off on pruning for a while. I've got it propped up with a couple 2x4s until it gets rooted.

Mack