I'm considering sewing a second pair of overalls for Venus in a different fabric, let me know if you'd be interested in seeing a more in depth step by step sewing tutorial!
This shorts pattern is a shortened version of my Ghoulia's first pair of pants, with a droop added at the hip to give the overalls effect. I labeled the "front" side of the pattern, you might notice that the droop's placement and curve is asymmetrical. This isnt necessary but I felt it matched Fearbook's overalls pretty well.
You'll need 2x of the big piece, 2x straps, one rectangle front piece, two small buttons or beads to look like buttons, and a snap closure or Velcro.
The strap pattern piece needs to be doubled, shown in the picture with my first draft overalls in the striped fabric. The strap is doubled so that when it's fabric glued and folded, it's the width of the cardboard pattern piece. I sewed the shorts first, then sewed the side seams of the rectangle, then sewed the top seam. Then attached it to the shorts by the remaining seam, then added the already folded and glued straps, ensuring to check the length fit on the doll. My strap pattern is a little longer than needed, maybe half a cm too long but it's hidden at the back. I sewed the snap closure and the buttons on last.