Here's a super easy pattern you might want to consider if you are into knitting for the American Girl doll. I made it on a midgauge machine, but if you use your own gauge and a different machine you can make an identical one. See the note at the end of the pattern.
Yarn: Acrylic worsted, 2 ounces main color; a few yards of finer yarn, two colors for corsage
Finished size: 8" x 8" measured diagonally from shoulder to bottom edge
Gauge: Tension 10, 4 st x 5 r = 1"
Directions
Knit two rectangles. Cast on 34 stitches and knit 36 rows. Bind off loosely. Sew the short end of one rectangle to the end of the long rectangle. Repeat for other side. When seaming, leave enough of a neckline to go over the doll's head. It will be snug. Hide yarn ends.Crochet an edge with size E crochet hook. *DC into the garment at the edge. Chain 3, DC into the same stitch as first DC. Skip one garment stitch.* Repeat from * to * around. Hide yarn ends. Mine came out really ruffly and the edge wouldn't lie flat so I steamed it pretty vigorously. Is lots cuter than it looks in the picture.
Crochet a corsage. Chain 6 and connect to first chain to make a circle. SC into circle 10x. Fasten off first color. Leave a 3" yarn tail. Change color. SC, DC, SC in the same stitch on the outside of the circle. Skip one stitch and repeat around to create 5 petals. Fasten off leaving a 3" yarn tail. Let the yarn ends dangle. Sew the corsage to the poncho.
To make on a different gauge machine, use your gauge to make the rectangles 9" wide x 5" long. Multiply 9 x your stitch gauge per inch and 5 x your row gauge per inch.
I'm thinking some apple green capri pants would be cute since I have yarn left over. I think Knitware has some doll garments. Will check it out. Stay tuned.
Afterthought: If you're finding the neck too tight, try again by adding 5 or more stitches to the width and this should make it easier to slip over the doll's head.