Specific Doll Dress model ID

I think that's an Acorn Chacha, but the faceup and angle make it look a bit rounder in the cheeks so I'm not 100% sure. It was only released as a head and has had two pre-order periods this year.

 

Have you tried emailing the site owner? Sometimes they can contact the owners to find sculpt names!

 

It's Acorn Chacha - link to head for comparison.

Edit: it took me so long to jog my memory, but this is the doll's owner, they've answered about the doll here