I considered that hypothesis, but the current text still mentions her having a “slim form”.
EDIT: Fresh new change, “slim form, smooth skin, slight curves” has been replaced by just “lithe form”.
EDIT2: I’m an idiot. I checked the wiki and the reason was much simpler: Petunia was actually supposed to have been thin in canon.
I considered that hypothesis, but the current text still mentions her having a “slim form”.
EDIT: Fresh new change, “slim form, smooth skin, slight curves” has been replaced by just “lithe form”.
EDIT2: I’m an idiot. I checked the wiki and the reason was much simpler: Petunia was actually supposed to have been thin in canon.