I recently acquired a Kershaw Baby Boa, which is an assisted 2" recurve. Pretty sweet. It's discontinued, but you can still find a few around, if you look.
The SOG Bluto is very similar at 2 1/4", but no assist. It, too, is discontinued, but can still be found if you look around.
Other small knives I like are the Spyderco Micro Dyad, Spyderco Ladybug, and Spyderco Dragonfly (gifted the "tattoo" version to my girlfriend). I have all three and I like them all. Excellent steel in each one. None, of course, are assisted opening.
Benchmade doesn't seem to make anything much under 3". Even my 530 and my Mini Grip are just under 3" long.
I was shocked to find that it is physically possible for Cold Steel to make something smaller than 4". The Micro Recon. Pretty snazzy looking, but the reviews are mixed. Think I'm going to order one anyway.
Kershaw makes a bunch of smaller knives, as you know. Here's one I hadn't thought of: The OD-2. 2" blade, manual flipper, liner lock in an FRN handle. For less than twenty bucks. That's now on my list, too. Girl pants have incredibly shallow pockets, so I'm thinking a small blade like the OD-2 might work well for her as a back-to-school tool.