Asami is pretty regularly drawn as more than just a couple inches taller than Korra, though. At least 3 or 4 inches, if not more sometimes. Ugh, official height charts would just make life easier!
There’s inconsistencies here and there, but when she’s not in heels it looks more like 2” to me. IMO this image is likely the most carefully drawn of them, and they’re both equidistant from the camera, so this is how we should be gauging:
Also yeah, start off the morning with this shot :)