I don't know how modern your machine is, but yes you can do it in one step. There is a foot that you slide your bodice thru one level, the skirt under the foot next to the feed dogs, and sew all together at once, gathering the skirt as you go (once you've set the stitches & tensions correctly). Or if your machine is older, you can do it with the lgr attachment--the 'pleater' that adjusts to gathers. I believe I am correct in saying the bodice would go underneath, and the skirt would slide under the teeth of the pleater and moves along faster than the bodice part.

Do, I have to buy a walking foot or a gathering foot? I have an old berina, but I just got a new Jem Gold Jamone 600, so that is fairly modern. It makes a tiny zig zag that my berina can't do. The tiny zig zag is for top stitching doll clothes around the bust line area even works on stretchy fabrics.

No, the walking foot will not do gathers. My simple little gathering foot that fits on my older Elna, is packed away in a closet. But I have several older attachments that pleat, and adjust to gather. Most of them orig. fit treadle machines, but will also fit most of today's machines--depending if short or long shank. Only the straight stitch is used. Here is a photo of one--you can see the fabric would be between the slot in front (right side)--the bodice would be underneath the attachment. The L side of the photo shows where it attaches to the shank and around the needle bar. At the top front is an adjustment for stitch length--this is how you control the fullness. I' maybe not explaining well, but you can prob buy a gathering foot that just clips onto your later model machine.

Janome does have a ruffler foot on amazon, but it is very expensive. There is a gathering foot but it looks just like a bulky foot. Maybe I can get a used one on ebay?

yeah! There you go! Ebay--''sewing machine feet'', One for your machine...it will look kinda bulky. That's what you need, and test with the tension + stitch length until you have it as you want it.

Upon asking someone else maybe a rufflers is too extreme for what I want to do. I got the idea, I should post a photo of what I want, but I think they make these with sergers by adjusting the feed to make the fabric ruffle on the shirt. I know they do these with one step as these are from the dollar store.

Yes, you CAN gather with a serger--but looking at your pix, it would seem as easy to run a double line of stitches and pull the bobbin threads to gather it up before joining to the bodice. OR, zig zag over a heavier thread and pull that to form gathers. Easy and certainly cheaper than buyin g a specialized foot. Good luck, whatever your decision.

Yes a 60. Dollar foot sounds like over kill, unless I used it often, but if it would make it really easy, then it could be a good idea. Using a serger, I have one, what dial setting would make one side the skirt pucker up but the bodice remain smooth?

Get out your manual for the serger. Settings for one serger won't necessarily work for another.

Check under sewing knits with the differential feed. It will tell you how to set your machine.

I still want to get a ruffler, because it would be easier to not have to get out the serger, if I could get one cheaply. I know there is a ruffler I could buy for under 20 dollars, but would it be able to make this type of doll dress? Or would it be too extreme and I really should use the serger? Also the serger is pretty heavy to take to crafting sessions. I wanted to sort of make these with a machine. It takes too long to thread the serger.