Her gown was a replica of the one Audry Hepburn wore in Sabrina. There has been some talk (not all good) about her choosing that beautiful gown. This is what one of Audry Hepburn's sons said about it:

“It is no wonder that growing up in a family which knew our mother as a household name she chose to draw inspiration from her,” Ferrer told DailyMail.com in a statement published Jan. 22, “to seek the ultimate elegance and class reference, for an occasion such as this one—the inauguration and the 32nd anniversary of our mother's passing and, most of all, Martin Luther King's day. What a cocktail!”

I think that is just wonderful. I'm an Audry Hepburn fan and I was surprised at the things I've been reading about Ivanka's choice. Most of it good, but some not so much.