Look at this 1930's needlework and sheer chiffon collar jabot. So suitable for your vintage dress, the collar is three tiers, or layers, in graduated sizes and lengths.
It is styled with a round neck line with a snap closure at the back. Chiffon is a beige color with a creamy needlework of small circles trimming the scallop edge.
Measurements: 16" around the neck opening, from one side to the other. 6-1/2" long from center front to the bottom at the hem.
Condition is very nice. Possibly was never worn but if so, only slightly.