While filming for the eighth and final season of the hit TV show ceased last year, Williams says she keeps in touch with the rest of the cast via the messaging app.
Speaking at the Glamour Beauty Festival in London on Sunday, the 21-year-old admitted that the cast us the group to mostly share funny pictures of eachother – and that we might one day be able to see them.
“We have a Game of Thrones WhatsApp and people just post really funny pictures of one another from various seasons,” she said.
“I think there was a rule that these do not go on Instagram… but I’m definitely going to put them on Instagram.”
The actor, who plays Arya Stark in the mediaeval fantasy epic, also spoke about the close relationship she has developed with the cast, describing them as “one big family”.
“I've been close with her for a long time. When I first met her she didn’t have any kids and I was 12-years-old and now she’s a mother of two,” she said.
“We’ve been with each other for these crazy times in our lives.
”Knowing someone for a decade is huge and she’s always treated me like a grown up. She always respected me on a real level and for that I’m so grateful.“
Williams also revealed the lengths the Game of Thrones showrunners went to in making sure the secrets of the finale were kept airtight, admitting that while she has told her mum the ending she’s careful not to ruin it for fans.
In a recent interview with Glamour magazine, the actor said you would have to get her “very drunk” to reveal what happens, while her co-star Sophie Turner, who plays Sansa Stark, confessed to having already spoiled it for her boyfriend Joe Jonas.
“I've just told Joe. But he's so mad at me – he loves the show,” Turner said.
“Well, I have to tell someone, otherwise I'll burst."
Game of Thrones returns on 14 April. Viewers in the US can watch on HBO while Sky Atlantic and NOW TV will simulcast every episode in the UK. Find out everything we know about season eight here.
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