Nevermind, I'll try to do my best...
I drew a modern pattern with six seams. I also tried to use krea's period pattern, but sis wants to wear bra under the dress and the pattern with two seams didn't work.
When I had the top fitted, I measured the length from each seam to the ground on my sister. I made the skirt in the same way as the full circle skirts, but this one was only half a circle (for the upper edge: o=pi*r where o is girth). I folded the canvas for the middle of each piece to be bias. The skirt should sweep nicer this way.
I sewed the skirt in the side seams, and I made an extra back seam to create a slit under the top.
I put the skirt on the top, right sides together, and sewed in the marked line.
You may notice that I have already made sleeves as well (the easiest shirt's ones) and that I ironed vlieselin to the center front seam allowances. It will be three layers of fabric and two of vlieselin thick so that the lacing wouldn't wave when tied firmly.
When I was hemming the skirt, I used a little trick. If you have ever hemmed a wide skirt, you know the edge tries to escape as it's wider than it whould be. I serged the lower edge and used a differential feed higher than 1. That causes the serging to gather the fabric. After ironing the hem, sewing was very easy.
I left the sleeves long, because they should be pulled up to support the slit parts of the sleeves on the upper dress. I don't know yet how much of the sleeve will be necessary.
