I've made it in Sirdar Baby Bamboo (80% bamboo, 20% wool DK) for my daughter, in the size XS with a few judicious additions and
Most of my changes were at the back. This cardigan is knitted from the top down, and as written has a very straight neckline. In order for the neckline to sit higher at the back than at the front, I added 10 short rows, tapering at the sleeve increases at the back.
I also found the cardigan to be a little tight for my daughter across the back (the advantage of knitting from the top down is trying-on opportunities), so added a few stitches here also.
In the pattern, the waist cabling starts at the bottom of the ribs. I was knitting away merrily in stocking stitch on automatic pilot and failed to refer adequately to my pattern at a crucial moment. This means that I had knit nearly 9 inches of stocking stitch instead of about 9 cm, so my waist cabling is a little shallow, due to a dislike of frogging perfectly good knitting.
This does not bother me particularly, as I still think the cardigan looks great - with jeans, shorts or even with office clothes.