The dress design and print is Magic Tea Party, Plus size alternation service provided by Night Whisper. 
Name: Christmas Sweets/Christmas Cookies
Material: Thick Cotton ( a lot of customers report the fabric feels like canvas. It will be soft once washed. Also thick cotton is way more expensive than polyester.....)
I extended shoulder straps, bodice, and skirt, added 2 pockets. 

2XL-4XL: for bust 47“-55”/120-140cm, waist 40"-50"/100-130cm, length around 42"/106cm
3XL-7XL: for bust 51"-65"/130-165cm, waist 44"-61"/112-155cm, length around 43"/110cm