Chapter 5 of Crazy Rich Asians finds Astrid attending a ball in Paris. She wears a Madame Gres  linen gown to the ball, similar to one the hostess had seen at the Musee Galliera.

Madame Gres was a famous coutouriur in Paris from the 1940’s to the 1980’s. She was knows for her goddess gowns, perfecting pleating and draping to celebrate a woman’s body.

The Madame Gres Wikipedia page

You can find Madame Gres garments for sale at 1stdibs.com where Madame Gres items range from about $750 to $25,000.