I used the master pattern for Size 3 Toddler pants, pattern pieces 16 & 17 to make a pair of jeans with a different fabric for the cuffs. Kerstin has directions in the book on how to make the cuffs.
What is interesting, is that in the Toddler book, the directions for making the pants, is not the easy way. (Where you put one pant leg into the other, then sew up the crotch.)
I had to go to her book Kwik Sew's Sewing for Children to get the better pant sewing directions, and a "little" bit better visual explanation of how to do the cuffs. Just a very "subtle" difference in the explanation/diagram, but it made all the world of difference for me.
Plus, since the fabric had a direction to it...pumpkins, I of course, cut the cuffs out in the WRONG direction. So, I had to redo the cuffs. Yes, I only did one the incorrect way, so I didn't have to "unsew" two cuffs....argh!
I was trying to do this of course, quickly. And I wanted to cut out a pumpkin shape to applique onto a shirt, but, just not enough time to do this......
And it looks like the pants are too big! size 3T in McCalls and 3T in Kwik Sew are a bit different.