I love your question bc I sometimes feel like the shorties get ignored in the outdoor world!? For reference, I'm female, 5'2", 125-ish (sometimes you have a bad day), 32C, narrow hips. I have many many miles of experience on trails of all kinds and in all places. My base weight tends to be around 11 lbs, with exception of the winter and with the addition of miscellaneous luxury items, trip dependent.?
I hiked?the JMT NOBO in 2022 in about 15 days, mostly solo.
For many years, and on the JMT, I used the REI Flash 45L, which REI only now make in the 55L size. It fit my Bearikade vertically, but snugly. It remains my favorite pack - distributed the weight extremely well on my (narrow) hips and so comfortable on my shoulders bc the padded straps were wonderful.? It finally succumbed to my abuse after a desert outing which required a 10L water carry, far exceeding it's max weight limit. I mention this pack even though they've long stopped making it because I feel like the new REI Flash packs might warrant a look if your are near a store and are often on sale. And honestly, if not for the terrible squeaking and sometimes weird frame bending, I would patch the holes and continue using it.
Currently, I use the ULA Ultra Ohm 40L. It fits well, carries weight well, and besides being a bit floppy, is overall a great bag that I would recommend. I have a size small bag with size small hip belt, which is probably just a bit big for me, and use the S straps. The hip belts are adjustable so over a few trips, I've moved it up and down to dial in the fit. The biggest adjustment for me was brain-withdrawal and figuring out new ways to organize my gear. The ultra fabric is nice (although somehow I made a hole in the front mesh). I?have had it out for shorter trips and once a couple months ago fully loaded out for winter (double quilt, all the treats), and it has carried the weight and volume no problem. I do think the zipper on the hip belt pocket goes the wrong way, but that's not fit related.
One of my weird nit-picky things. I have a small frame and many packs seemed too wide for my body and I have a weird imagining about unobstructed arm swing, which really isn't a thing except in my head. That is why I favor packs around 40 ish L, vs the larger GG packs or even the newer REI Flash. I have never had trouble fitting all the gear I need or want into the Ohm 40, but this is where YMMV.
Unfortunately, you are correct that you need to order and try, which takes a ton of time, and is a hassle. Just like ordering petite length clothes online bc they're never in the store! I was able to play around out my friend's XL Circuit (I know, not at all the same), and took the plunge. Luckily ULA have great customer service and it fit me well enough that I kept it and didn't experiment more.
Also, like many people, I use an inReach mini. This has been critical because I really love solo trips and it gives me and most importantly, my friends and family, peace of mind. I have the older version and see no need to upgrade at this point.
Hope this helps. Feel free to also ask about other short-person gear I've accumulated!
sharon