I found out that Kelly doll patterns are sized somewhere in between a kid and an adult Sylvanian Family member. (At least, that's what I recall.) So I started with Wendy Squires's pattern for a 'Ruffle Tank Top', and of course modified it in all sorts of ways to make it fit. Here is "Quick Rewards, #1", as I have called the project on Ravelry: It was made in a size 10 thread with a 1.5mm crochet hook. I couldn't figure out how to close the back for the longest time. Then eventually I decided to make a chinese button knot. I found instructions on Chinese Knotting, and after numerous practice attempts with larger cord and many failed attempts with the size 10 thread, I eventually managed to create a button knot closure.
The first dress went together so fast I moved onto "Quick Rewards, #2", an outfit for Fern Timbertop. I used Wendy Squires's "Victorian-Style Outfit", and again modified it. This time, however, I kept track of my modifications (more or less); they're written up in my project notes on Ravelry.
For "Quick Reward's, #3" I decided to try knitting instead of crochet. I pulled out the smallest needles I had (at the time), 000 (3-0), and some DMC Perle 12 thread, and attempted to make a pair of underwear using "Undies for Barbie" with the usual modification creativity for fit. Modifications are again listed in my project notes, but I was starting to keep better track of specifics by this point so they may actually be complete enough to duplicate this. I concluded from this project that I needed smaller needles, and I needed to use finer thread.