Kate Middleton's Seraphine dress, worn for their first official royal family portrait, is already sold out! Credit: Michael Middleton/Kensington Palace via Getty Images

The fuchsia dress Kate Middleton wore for the royal family's first official portrait with baby Prince George is stylish, flattering — and already sold-out! It's been less than 24 hours since the picture of the photogenic trio was released worldwide, but demand for the Seraphine Maternity frock was so high that it's currently on back-order.

The figure-forgiving, flowing empire-cut "Jolene" dress, costing just $79, hits just above the knee and is draped in the front. A deep  v-neckline "pulls aside for breastfeeding," notes the company's website, which also states of the dress: "Due to high popularity of this style, please be advised that orders will be dispatched the week commencing 16th of September."

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In an interview with Hello! magazine on Aug. 20, the president of Seraphine Maternity, Cecile Reinaud, talked about the Duchess' effect on the brand. "The Kate effect is huge and we have been enjoying a 400% growth in sales since it became public that Kate bought Seraphine dresses back in April 2013," she said.

Not surprisingly, the three dresses from the label that the Duchess has worn are clearly labeled on the website, "Worn by Kate Middleton."