21st Annual Screen Actors Guild Awards - Red CarpetStark sisters 4EVA. "Game of Thrones" star Sophie Turner (Sansa Stark) turned 21 today, February 21, and her on-screen sister Maisie Williams (Arya Stark) honored the milestone with the sweetest b-day post.

Turner and Williams have been close friends from the start of the HBO show, which began filming in 2010 for its 2011 debut. Williams will turn 20 on April 15, so she was barely a teen when she first met Turner. A lot has changed in the past several years, but one thing remains the same: Turner is way taller than Williams. Their love for each other hasn't changed either, and Williams worked both angles into her cute birthday post:

All together now: Awwwww.

Turner's height is listed at 5'9" and Williams is 5'1", but when it comes to the Stark sisters, Arya is the real powerhouse. (For now, anyway.) We can't wait to see the Northern lasses back in action in "Game of Thrones" Season 7, which will show up sometime this summer.

Here are a couple of other great b-day posts honoring Turner's big day:

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