First I'd like to say thank you all so much for the responses! I came back today to ask another question about one of her behaviors that's been bothering me (posted in the Behaviors forum, as I don't think it's related to her having been feral), and I decided to scope out the Feral forum and found my topic still at the top, which surprised me.
Sorry for taking so long on the update, but I've been so enthralled by Onyx (finally ended up naming her!) that I didn't think of returning to keep you all posted.
This has turned out to be one of the most lovable kittens I've ever had. She's a complete lapcat--she'll nap in my lap for hours after eating, purring all the while. I don't have to grab her to get her here, either--she jumps up all on her own. I haven't heard a hiss out of her in weeks, either.
There was a bit of a problem with her pouncing my feet at night, but a few squirts from a spray bottle filled with water took care of that.
Now she plays by herself at night and munches from the bowl of dry food I keep out for her 24/7. I know dry food isn't the best choice, but I'm having a hard time fattening her up because she's growing so fast, so I figure the carbs may be a good thing for now. =/ I feed her wet food every six hours while I'm awake, put wet food down for her just before I go to bed, and leave the dry food available all the time.
Nowadays I wake up in the morning with a purring kitten in the crook of my left arm--waking up never felt so good. =D
I eventually removed the box that blocked off the hallway to the kitchen, since after a couple weeks she discovered she could easily leap over it as long as she had a running headstart, lol. Now she considers the kitchen her territory too. The only time she's gone behind the fridge is when I was gone for 10+ hours on a trip to my hometown for my little brother's junior high graduation. I came home to find an empty apartment, and panicked. I searched all over for her, went to www.homeagain.com
to double-check that her microchip was registered to the right address, tried to peer up my fireplace flue even though the screen hadn't been moved...as soon as my mom left, out crept a very disgruntled black kitten, lol.
I've successfully introduced her to my little brother, though, who's here on a week-long visit to start off his summer vacation. She wouldn't go near him at first, but now spends a significant amount of time napping in his lap too. =D
Mitts & Tess - your suggestion of a rolled up towel will definitely be put into practice, thank you. =D Also, luckily, I don't have an actual bed, just a futon. There's nowhere to squeeze, though she does like to hide under the futon when we're playing with one of her mice-on-strings.
I think she is probably asking her litter-mates to stop hiding. My cat who lost her sister after 15 years would walk around constantly looking for her (despite the fact that they didn't really like each other when they were growing up!)
I probably should have thought of that, actually. I had a cat, Patches, for 15 years, and I finally made the decision to put her to sleep two years ago after fighting a losing battle with cancer. She'd lost all bladder control, couldn't keep down any food and was getting horrifically underweight, and had even given up her spot of sleeping on my butt at night to curl up on the cold kitchen tile. ;-; The minute my mom and I returned to the apartment (with me sobbing hysterically, it was awful), my mom's cat Ebony started asking where she was. They'd never liked each other, and in the past year or so had called an uneasy truce, but Ebony searched for her everywhere, calling. I guess I should have recognized the calling voice.
So all in all, things are going fabulous. I'm completely in love with her, and can't wait to spend the next 14+ years waking up to this adorable black face, with the one stray white hair between her eyes.