Maisie Williams has sent her 'Game of Thrones' co-star Sophie Turner a sweet message on her birthday.

Maisie Williams and Sophie Turner Instagram (c)

Maisie Williams and Sophie Turner Instagram (c)

The 19-year-old actress - who portrays would-be assassin Arya Stark on the HBO series - shared a throwback picture of herself several years ago peering up to her much taller pal, saying that she will "forever look up" to her on her birthday yesterday (21.02.17).

Alongside the old photo, she wrote: "Happy 21st Birthday @SophieT Forever looking up to you, in more ways than one (sic)"

But Sophie - who has played Sansa Stark in the fantasy drama series since 2011 - replied saying she idolises her too.

She added to the micro-blogging site: "@Maisie_Williams nah. Looking up to you, kid. Love you (sic)"

Meanwhile, Maisie recently said she is ready to make "bold decisions" about her career after 'GoT' draws to a close in 2018 because she has always had the "safety net" of playing Arya to fall back on when she didn't land roles she'd auditioned for, but she's looking forward to trying new things.

She said: "It has been my security blanket and it's been a safety net. If I haven't worked, or if I haven't landed a role, I never beat myself up too much, because I've always got 'Game of Thrones'.

"To not have that around is going to be really strange, but it's also really exciting. It means I can now shape my career and I'm not tied down to anything, and I can really make bold decisions."

And though season seven of the fantasy drama hasn't yet aired, she is already thinking about the end for her feisty alter ego.

She added: "I'm just trying to do the last few scenes that I have justice. I'm just trying to shape Arya the way that I have been so far, and give her a nice arc to end with, and hope the people are happy with it."