As promised, here are some pics on how I worked the hem.
I started with a provisional cast-on. I used the directions in Barbara Walker's Knitting From the Top, but I don't think it matters what kind you use. I used some of the pink Calmer for waste yarn. Then I knitted the hem as in the T-shirt pattern.
Then I slipped the cast-on stitches to another needle. I used a size smaller to make life easier.
When you get to the end, count the stitches, make sure you caught them all. Then pull out the waste yarn.
Then I k2tog, one from the current row with one of the cast-on loops. Just like a 3-needle bind off without the bind off part.
Tada! Ready to start knitting in pink for the rest of the piece.