Vintage Black Negligee Lingerie Nightgown Size Medium?

The size tag has been removed or it is unreadable on the tag that is there. It is machine washable. There are a few lighter colored marks under the left breast skirt area. Please see photos for Marks and measurements. The elastic stretches to 18 1/2 o niches under the breasts. Smoke-free and pet free home Questions? Leave a comment below! M-5