White Organdy, widely flared skirt
Trudy (Hutchison) Hotson, who knew Mary Jo and who graduated with her remembered the following about Mary Jo's dress: At graduation she wore a white filmy flowing dress with silver sparkles in her hair Trudy wrote this in February 2008, 69 years after their graduation and after never having seen any diagram of Mary Jo's dress
Organdy was a natural material that is light and sheer like chiffon but stiff and holds its shape like tafetta.
Widley flared means that the dress, as drawn in the diagram, is very wide at the bottom.
The lace embollishments at the front of the dress were not necessarily described but rather added by the artist.