It is a three-piece ensemble consisting of: 

• a sheer Swiss dot sleeveless dress that buttons up the back and has a snap at the neckline; 33" from shoulder seam to bottom of the hem, waist is 12" from side seam to side seam for 24" total, chest is approximately 15" across for a total of 30"
• a sleeveless solid lace-trimmed under slip that snaps up the back. The lace trims the bottom of the slip, the neck opening, and the armhole openings. The waist and chest measurements are similar to the dress's measurements, but the length differs in that it is approximately 30" (so as not to hang longer than the dress).
• a lined Swiss dot short-sleeved cropped-length jacket that also buttons up the back. Lace trim on the short sleeves, neckline, and bottom hem. Front and center at the bottom are three buttons, and the jacket has a cute inverted cut. It measures 12" from the shoulder seam to the bottom of the jacket, and the chest measures 15" across the front for a total of 30" all around.

I have no idea on the exact size, but by today's standards, it would probably be considered a Small. Hopefully, the measurements above will help you determine the fit. 

Please study the pix to see the details and stitching quality of each individual piece. 

Thanks for looking; please bid.