Rosie is the most demanding sweater I have made in this series. That is worth saying straight out.
Half brioche, eyelet pattern and puff sleeves in the same garment. It is marked Lightly experienced — the level I use when you have to keep track of more than one thing at a time.
That does not mean the stitches are hard. All three techniques turn up on their own in patterns marked Beginner plus. What makes Rosie demanding is that they meet.
My advice: knit a gauge swatch where you work all three one after the other before you cast on for the body. Then you know how the transitions feel, and you don't have to work it out in the middle of a sleeve.
If you are unsure whether you are ready, you probably are. And if you get stuck, all three techniques are explained with video in Knittipedia.
Lightly experienced · needle 7 · half brioche, eyelet pattern and puff sleeves