See Natalie Portman's Slim, Stunning Post-Baby Look!

Aleph has got one stunning -- and slim -- mama!

Five months after delivering her son Aleph, first-time mom Natalie Portman made one of her first semi-official Hollywood appearances on Thursday night.

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Portman, 30, was among the stars at a live table read of the screenplay for The Apartment, the classic 1960 romantic comedy starring Jack Lemmon and Shirley MacLaine.

PHOTOS: Jaw-dropping post-baby bods

The Oscar-winning star (engaged to Aleph's daddy Benjamin Millepied) gave a glimpse of her slimmed-down post-baby bod in an adorable, preppy-chic outfit that recalled Audrey Hepburn: a thin red cardigan worn over a pinstriped button-down blouse paired with skinny jeans and dark brown flats, with minimal makeup and her hair in a simple ponytail with sideswept bangs. Her only jewelry? Her gigantic engagement ring from fiance Millepied.

Reading the famous script with Steve Carell, Pierce Bronson, Ken Jeong, Mindy Kaling, Jason Reitman and other actors, the fresh-faced actress kept cheerful and professional throughout the reading.

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No official word yet on what the Black Swan star's first post-baby film project will be -- or when she and dancer-choreographer Millepied, 34, will wed.