Honestly, I think you are totally right to be confused, I just fell down this rabbit hole looking at the standards, and the info online is super contradictory!
I think I figured out exactly why the numbers don't add up. That 36-inch stat you see in the AI overview I think is misleading because it conflicts with the breed standard math. If a 22" tall female was actually 36" long in the body (measured breastbone to butt), she would have the proportions of a Dachshund! That 36-39" number likely implies measuring the total length (nose-to-tail) or is just pulling from a bad source, because the official AKC standard actually doesn't list a required length in inches at all.
The AKC standard only lists the height and the desirable proportion of 10 to 8 1/2. If you do the math 10/8.5, the ideal ratio is roughly 1.17. Since your girl is about 30" long and ~25.5" tall, your math 30/25.5 also comes out to roughly 1.17. So, mathematically, she is actually perfect! Just to be 100% sure, the standard specifies measuring length from the prosternum (point of the breastbone) to the ischial tuberosity (rear edge of the pelvis). If you measured between those two points and got ~30", she is exactly the correct proportion and definitely not too short. This is a concept I'm not extremely familiar with though, so if anyone else can confirm that, that would be good!
