It is easy to pad a smaller form up with quilt batting or foam to match your curves, but you cannot "shrink" a rigid form if it is too large in even one area. Essential Selection Guidelines
When buying a dress form for sewing your own clothes, ignore your off-the-rack dress size. Instead, . what size dress form should i buy
How to pick the right dress form size? - Sewing Pattern Review It is easy to pad a smaller form