Per
@DdBob 's recommendation, we ordered Kiira a Ruffwear front-range harness. Her current harness (that we got from the rescue organisation) is obviously a very good harness, but it just doesn't really seem to fit her body type all that well. It wiggles around her shoulders in a way that doesn't seem all that comfortable, and the back strap has a less than ideal fit around her waist. It's not bad and she doesn't mind putting it on most of the time, but we think something else with more padding and a broader pad over the shoulders might be a lot more comfortable for her. Let's see if the Ruffwear harness works better.