I credit the vinegar rinse. After just doing it *once* I could watch her skin react before my eyes (and it didn't seem to cause her any discomfort). This morning, even after wearing a diaper all night, her bum is much less angry.
If we just stay on top of it for the next two days, and keep up with what we've been doing, we should be out of the woods.
To say I am much relieved is a huge understatement.