White flowy dress

This dress is beautiful and in great condition, adjustable at the shoulders. There is some yellowed markings on the inside of the straps where it touches the body but not noticeable when wearing. There are little spots on the dress where I am pointing to but I haven’t tried washing and it may come out. They are very hard to see. I would say this fits like a small. I am 99% sure this is Guess (I bought it a long time ago).