Liv Tyler [1] looked happier than ever while hanging out at Stella McCartney's Resort collection launch [2] in NYC on Monday. The actress was all smiles while posing for photos with the designer, as well as celebrity guests Alicia Keys [3], Alexa Chung, Cara Delevingne, Miranda Kerr [4], and Maggie Gyllenhaal [5]. It was likely a fun moms' night out for Liv, who welcomed her second son [6], Sailor, with fiancé Dave Gardner back in February. Since then, Liv has given glimpses of her baby boy via social media [7], as well as fun snaps featuring another member of her family: her famous father, Steven Tyler. Liv recently shared an adorable video of them singing a duet [8] to Frankie Valli's "Can't Take My Eyes Off of You" while lovingly looking into each other's eyes. Keep reading to see photos from Liv's exciting evening at Stella McCartney's fiesta-themed collection launch.