It's difficult to believe that only four months ago Mila Kunis gave birth to her daughter Wyatt, her first child with partner Ashton Kutcher. Last night she showed off her very trim waist at the L.A. premiere of the new film Jupiter Ascending in a gorgeous black Dolce & Gabbana dress with a corseted bodice and full skirt. She topped off the look with Christian Louboutin heels, a Bottega Veneta clutch, and Gemfields ruby jewelry by Miiori.

So did she maintain a gym routine? "You know, it's called baby. Breastfeeding's a great workout!" she told Craig Ferguson on The Late Late Show in December.

Kunis has been on the talk show circuit lately to promote the upcoming sci-fi film, which also stars Channing Tatum and Eddie Redmayne. Last week she went on the Ellen DeGeneres Show where she was pressed for details on her marriage status. Ellen DeGeneres was especially curious because on New Year's the couple put a message on Instagram that said "Happy New Year, [heart symbol] the Kutchers," leading many to wonder if the new parents had tied the knot (they became engaged last February).

"I don’t know," she told DeGeneres. "We could just be a plural. My daughter has his last name legally." Watch Kunis gush about her new baby girl in the clip below.