This petti can be made for any doll, you just need to measure the doll's waist and the length you require it to be. My doll's waist was 14.5 cm and the length I required was 20 cm without the lace, so a cut one long strip 12 cm wide (half the length, plus 2 cm for seams) x 116 cm long (the width of the batiste I had selected). Then cut 36 cm (approx. 2.5 times the waist measurement) off for the basque, leaving the remainder for the frill.
Beginning with the basque, I neatened the seam edge: First fold 5 mm over, press with an iron and machine stitch, then placed the two neatened edges right sides together and run a seam half way. At the waist edge fold 5 mm over, press it then fold 10 mm over again, press it then machine stitch it to form a casing for the elastic.
Then I added the lace to the bottom frill, seamed the back as I did for the basque, but all the way from the bottom to top. To gather, run two rows of stitching (set on longest stitch and securing at the beginning of each row but leaving the end threads) about 5 mm apart. Pull the underside threads up until the gathered edge matches the basque.
Pin the two right sides together, easing the gather to fit the basque evenly, then run two rows of stitching around before neatening the raw edge with a small zig-zag stitch.
Turn your garment the right side out and it should look like this.
I added a further row of lace just above the seam between the basque and frill, over lapping the end and turning the edge under so no raw edges showed.
The final touch is to thread elastic through the waist casing, stitching the ends of the elastic securely so it doesn't pull through, then stitch a press stud (snap) on to close it at the back.
You may also find this a useful tutorial to make a tiered skirt.