Have you made the "smocket"?

Has anyone actually sewn this pattern?
http://www.themayfly.com/weblog/2007/02/happy_smocket.html

I printed the PDF and sewed it together hoping for approximately a size 2T (as described in the tutorial) but when finished, it barely fits my 13 month old daughter.  The pattern doesn't include seam allowances so I kept that in mind when I cut the fabric -- so that's not the problem.  I love, love this smock and have so much appreciation for people who take the time to post free patterns and tutorials -- I'm just trying to figure out where I went wrong.

Any ideas how to enlarge the pattern by hand (not on a copier)?  How can I know approximately what "off the rack" clothing size I'm making?

Thanks!
susan

Yes, I have made the smocket.  It definitely runs on the small side, but it did fit my two year old.  She is on the small size.  Sometimes babies are little chubbier, although smaller.  Maybe it will fit better once she starts to slim down?  Just a thought.  If I make it again, I would definitely make the ties longer.  They are on the short side for sure.