Vintage Navy Plaid Bell Applique Dress: 18m?

Vintage navy plaid dress with white Peter Pan collar, red trim, and red bell appliqué. Puff sleeves, gathered bodice, button front.

Not tag for brand or size. Measures 18m. 

Vintage dresses often run short. Please confirm best fit with measurements in photos.

Flaws: Elastic in sleeves has lost most stretch