Henwick's mother is Chinese-Singaporean and her father is British, and she was born and raised in England. She has described herself as a "Singaporean-Brit".
With her starring role in the childrens' series Spirit Warriors, she was the first East Asian actress to play the lead role in a British television series. Speaking with The New Statesman, Henwick commented on the restricted casting of Asian actresses on English television:
- "In British TV, if there is an Asian character there usually has to be a reason for them to be Asian, whereas in America you have a lot more roles where the person just happens to be Asian," she says. Henwick reports that her white counterparts get five times more auditions than she does and that many Chinese actors are asked to play tokenist roles. Progress is being made, and she cites a recent jump in the number of British Chinese actors gaining visibility as positive. But depressingly, she also notes that her Eurasian features prevent her from playing the usual role of an 'opium prostitute'...Because of the dearth of prominent British Chinese in the media and politics, some feel like they are striving on their own. “I do think it has an impact," says Henwick on the lack of role models. “Like when I was reading books, I always imagined myself as the lead character, male or female, doesn’t matter. But if it doesn’t reflect you, doesn’t reflect the lifestyle you lead, you won’t pursue that career path."
On Game of Thrones
In Game of Thrones she is playing the part of Nymeria Sand in the fifth season, one of Oberyn Martell's eight daughters known as the "Sand Snakes", in reference to their bastard surnames "Sand", and their father's nickname "The Red Viper".
In the novels, Nymeria is the daughter of Oberyn and a noblewoman from Volantis, one of the Free Cities, on the continent Essos to the east of Westeros. The TV series expanded on the idea that her mother was a "noblewoman from the east", to say that Nymeria's mother was actually from the very far east of Essos, apparently from Yi Ti (the narrative's fantasy analogue of Ancient China).
On training to use Nymeria's signature bullwhip weapon, Henwick said:
- "Nymeria is the most strategic of the three sisters and I think her whip is very representative of her character. It's not about brute force with a whip... it's about balance and timing, precision and accuracy — and all those things are very much Nymeria...Because of our different personalities we have different ideas of how to get to that point. If Obara has an obstacle she goes right through it, whereas Nym will stop and look back and think, 'What's the way with which I have to expend the least amount of energy to get through this obstacle?' She's observant, I'd say.
- I had six months between my first session and us actually getting round to filming the fight scene. I worked with Paul Shapcott, who is from New Zealand and worked on the Hobbit films. He knew the bullwhip and he taught me how to hit targets. At one point he was throwing toilet rolls into the air and I was having to hit them out of the air....Other times he would put sticks in various positions around our rehearsal room and I’d have to go and wrap my whip around them, and then for the last one I'd have to lock it in place so I could actually pull the stick away. It’s like learning to ride a bike — once you know it, you can always go back to it. It's just about feeling the balance and the weight of it...Yeah! They made a proper whip for me that has a bronze handle. It's made from kangaroo skin, it’s 8ft-long and it’s really heavy. That’s the one I had to use for close-ups. Then for the majority of the fights, I used one that looked identical but the handle was rubber and plastic, rather than bronze. It was a lot easier for me; it didn't throw me off balance. And then they did have a standby whip, the third whip, which was just a handle. They said, 'This is in case it gets too dangerous,' but actually I never really worked with that one. The whole time I said, 'I've learnt it, I've learnt how to do it. Can I do it?'And they kept saying, 'No you're gonna have to use the safety whip.' But every time we got to set, I would use the real whip."
Once early in filming, Rosabell Laurenti Sellers (Tyene Sand) was standing a little too close to her, and the sun was in Henwick's eyes, which resulted in Henwick accidentally cutting Sellers in the shoulder when she cracked her whip.
After Henwick was cast to co-star in Netflix's Iron Fist Marvel TV series, she ran into a scheduling conflict for filming on Game of Thrones Season 7. She very nearly didn't return, and as she put it, the producers said that if she couldn't make her schedule work they wouldn't bother to recast the role, but instead Nymeria would simply disappear - never appearing again, without explanation. At the last minute, however, she was able to squeeze it into her schedule by making repeated international plane flights to juggle working on both shows.
|Season Five credits|
|The Wars to Come||The House of Black and White||High Sparrow||Sons of the Harpy||Kill the Boy|
|Unbowed, Unbent, Unbroken||The Gift||Hardhome||The Dance of Dragons||Mother’s Mercy|
|Season Six credits|
|The Red Woman||Home||Oathbreaker||Book of the Stranger||The Door|
|Blood of My Blood||The Broken Man||No One||Battle of the Bastards||The Winds of Winter|
|Season Seven credits|
|Dragonstone||Stormborn||The Queen's Justice||The Spoils of War||Eastwatch||Beyond the Wall||Episode 67|