News Maisie Williams Wishes Sophie Turner a Happy 21st Birthday With Amazing Throwback Snap -- See the Pic! By Jennifer Drysdale 6:46 PM PST, February 22, 2017 Now Playing hh:mm:ss Happy birthday to Sophie Turner!The actress turned 21 years old on Tuesday, and her Game of Thrones co-star-turned-BFF Maisie Williams couldn't help but celebrate with an amazing throwback pic from the beginning of their friendship. EXCLUSIVE: 'Game of Thrones' Star Maisie Williams on Saying Goodbye to Arya: I'm Trying to Do Her 'Justice'"Happy 21st Birthday @SophieT," Williams wrote on Twitter, alongside an epic pic of the two from years earlier. "Forever looking up to you, in more ways than one."Happy 21st Birthday @SophieTForever looking up to you, in more ways than one ❤️ pic.twitter.com/43cCih2KeJ— Maisie Williams (@Maisie_Williams) February 21, 2017Williams wasn't the only one spreading the love. Turner quickly took to the app to share a sweet note to her TV sister."@Maisie_Williams nah. Lookin up to you, kid," she wrote. "Love you." WATCH: Joe Jonas and Sophie Turner Get Goofy at Friend's Malibu WeddingTurner and Williams' love for each other isn't just displayed online -- it's written in ink.ET caught up with Turner at the Emmys in September, where she opened up about her and Williams' matching tattoos: the date that they both found out they won roles in Game of Thrones.See more in the video below.EXCLUSIVE: Sophie Turner Flaunts 'GOT' Tattoo, Geeks Out Over 'Stranger Things'