Mr. Greenjeans for Joy

So I decided to start this sweater.  I was going to wait until I finished at least ONE of my other projects.  But I needed something new to provide visual stimulus.  And so far, I have just worked on it for this weekend.  I started it on Friday and it is coming along well.

I am starting to have some concerns though.  I was reading in the KAL group from Ravelry this morning and many people were having various sizing issues and such.  So, since I'm knitting this for Joy and she's a few hours away, how am I to be sure the sizing will be right?!  I figure I might be able to use Ashley for a rough sizing.  She's thin, but taller than Joy, but hopefully probably about the same size.  I'm knitting this in the medium size.

The pattern so far has been really easy to read.  Initially before I started, I did a simple swatch in Stock. stitch.  And since I'm nearing the end of that section, I decided to do the other swatch, which is the cable swatch.  Turned out well.  

At this point, I have 12 more rows to go before I pop off the sleeves.  And continue with the body, if I was sure on the size I would probably get to the point of the cabling start, but I'm worried, so I may hold off.  More to come on the progress of this.