Definitely butter. Ghost is sometimes difficult to tell in photos(or a single) with certain other lightening morphs like butter/lesser etc. If you didn’t say butter ghost I might have said pastel butter but I would be inclined to agree with the shop you got her from. I don’t see anything else that makes me think other genes are involved.
Looks like a pastel butter or lesser
Looks like pastel butter judging by the blushing. It’s a no on the hypo for me.