Maisie Williams has a ''close'' bond with Lena Headey.

The 21-year-old actress claims the 'Game of Thrones' cast is like ''one big family'' but she has a particularly special friendship with the 45-year-old actress - who has son Wylie, eight, with ex-husband Peter Loughran, and daughter Teddy, three, with spouse Dan Cadan - even though her character, Arya Stark, wants nothing more than to see Lena's alter ego Cersei Lannister dead.

Maisie said: ''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. 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.''

The British actress also revealed the cast are involved in a secret WhatsApp group, in which they mainly post funny pictures of one another, and she's vowed to make the images public one day.

Speaking at the Glamour Beauty Festival in London at the weekend, she said: ''We have a 'Game of Thrones' WhatsApp and people just post really funny pictures of one another from various seasons

''I think there was a rule that these do not go on Instagram... but I'm definitely going to put them on Instagram.''

Maisie admitted at the event she's told her mother how the show ends and she recently said she can't wait for the episodes to air so she can talk about them with other people.

She said last week: ''It's going to be a relief to be able to speculate once its all done and I can talk to people about the ending and what they all thought.''