I finally got a photo (two, actually) of Ivy free standing!
And then I got two more...
And even a video! (I still don't know how to turn them around and I should really just remember to film in landscape rather than portrait).
I found it amusing that she kept picking up the green triangle, dropping it, and picking it up again. Also pretty impressive to be able to lean over and then go back up to standing. Ivy tends to only stand when she is distracted, which is why she is holding something in all the photos. I don't think she knows she can stand yet, she just does it when she wants to use both hands for something else so forgets to hold herself up on something.