I bought the pattern for girls panties by Thatdarnkat. My thought was that it was a cute pattern and like swimsuits, panties are really big on my nerdlet and bear cub. I'm not sure how I feel about this pattern. It's adequate for what it is, but considering how easy it is to make something like this and how forgiving knit is, I'm wondering if I shouldn't have just adapted my panty/diaper cover pattern for a pari that fit my girls. As it is I plan to adapt this pattern still to be training pants for Darth Baby, who I still haven't potty trained (for multiple reasons).
Anyway, I made the straight size 2 for my 5-year-old. It is a really cute pattern.
The multicolor fabric is the fabric I used on my first attempt at the Tiramisu dress pattern and has very little stretch. Even with the lack of stretch, this size two fits her well. I imagine that a knit with a lot of stretch would result in panties that are too big.
The nerdlet really likes these so I guess it's a win, but I think if you have even the slightest inclination to try and make your own pattern for panties, go for it.