This is similar to, but not the same as Julie's tunic. You can make it more similar by finding that crinkly crepe that her tunic is made out of, but you'd still have to alter the bodice. My way is quick, dirty, and easy.

Could be historically accurate for Julie, Ivy, or a JLY.

You'll need:

Cloth -- Cotton is best. I'm using white, but feel free to go hog wild with colors.
A bodice pattern -- Just use a regular one. You won't even need to redraw it.
Sewing sundries -- Thread, scissors, needle, sewing machine if that's your bag ...
Optional: embroidery thread, hoop -- if you want to embroider it like Julie's. Embroider the bodice BEFORE you cut it out.

To cut your bodice pieces and back pieces, position them so about half of the piece is actually hanging off the fabric, then cut in. You're getting pieces that juuuuuuuuuust barely come to the arm pits. It will make sense when you see the picture.

To cut the bottom panels of the tunic, measure from about mid-chest on your doll to where you want the tunic's hem to fall, then add a half inch. Then, measure the bottom of your bodice piece, and multiply by at least 1.5. Cut three squares that are as long as the first measurement and as wide as the second.

So, cut two front pieces, four back pieces, two sleeves, and three bottom panels. Here, have a picture!

Hem the sleeves, and the three bottom panels.

Now, start putting everything together like a normal shirt. Sew the shoulders together like normal. Do this for all six bodice pieces.

You should now have two bodices. Sew them together at the neck, then turn them inside out.

Gather one of the bottom panels so that it's slightly larger than the bottom of one bodice edge.

Do this for the other two remaining bodice edges and panels. Now, pin each panel to an edge.

Put the arm in the armhole. Remember how we made the bottom panel slightly larger than the bodice? This gives you a tiny edge. Pin the edge of the arm on that edge, just like normal.

Finish the tunic like normal, folding everything over and doing the side seams. Make sure to catch those arm pits so you don't have any holes!

Put velcro on like normal, then enjoy.