Vintage Maison Petite Dress - Size 4/6?

Excellent vintage condition, purchased at a vintage store in Kensington T.O. My bust isn't big enough to fill it out, I'm about a size 4 30D for reference and it's too big up top for me. measuring approx: 15" across bust 13" waist 17" hips No information on the fabric, but it feels like a linen blend to me