This may actually be the wrong dress for her altogether. She may intensely do something for her wedding day but if she doesn’t keep it up it’s actually going to be worse on her body than if she never did anything. Yo-yoing is a killer. I hope she keeps it up After the wedding for herself and her well-being.
The dress is a poor fit... not her shape... it actually looks to be too long on top, that's why it's bunching up. Probably the wrong size, done on purpose for the show.