She became a household name playing kooky Orla McCool in comedy sitcom Derry Girls. Yet, Louisa Harland’s latest role sees her swap television for theatre, in Brian Friel’s Dancing at Lughnasa, where she portrays Agnes Mundy – one of five unmarried sisters living in rural Co Donegal in 1936.

Reflecting on her new part, Harland says: “It’s terrifying. We’ve been in previews for the past week which were technically rehearsals, and Tuesday was the opening night.”

The 30-year-old stars alongside some of Ireland’s finest thespians at London’s prestigious National Theatre, including Ardal O’Hanlon, Tom Vaughan-Lawlor and Justine Mitchell.

Luckily, her fellow castmates have been quick to offer their pearls of wisdom. “Of course they’ve given me some advice,” she says. “They’re the best. It’s a pleasure to work with Ardal again, as we got on so well in Derry Girls.

Harland (second from right) with her 'Derry Girls' castmates

“And obviously Siobhán [McSweeney] is one of my best mates. I mean Tom Vaughan-Lawlor and Justine Mitchell are the best actors in Ireland; my only fear is that I’m going to drop the ball,” she confesses.

The Dubliner admits it was a real pinch-me moment to have landed a role in Friel’s masterpiece, and she still can’t believe her luck.

‘This is my dream gig,” she says.

“I’m just happy to be employed – ever, but to be on this stage, doing this play with this cast is probably the proudest achievement of my life so far.”

But the star assures me she had to earn her stripes for a place in the production – which runs until May 27 – and wasn’t a shoo-in.

“I just auditioned. I did the play for my Leaving Cert, so it’s a full circle moment. I’m delighted,” she says.

Harland has come a long way since she made her teenage debut in 2011 as John Boy’s (Aidan Gillen) daughter, Kayleigh, on RTÉ drama series, Love/Hate.

Ardal O'Hanlon. Photo: Tony Gavin

She’s spent the past decade honing her craft in the English capital where she’s based, but admits home is where her heart is.

“I do love London, but I miss home so much. London certainly keeps me driven, and it’s kind of an uncomfortable place to live. And again it makes me feel like I’m here for a reason,” she says.

Fortunately, the Dundrum native has a special someone to ease any homesickness – and he’s also immersed in the arts world.

“My boyfriend [Calvin Demba] is an actor as well.

“He’s been in loads of things – he can’t stop working,” she says.

Siobhán McSweeney. Photo: PA

“He was just in this massive Amazon series called The Rig, and it’s about to go for a second series. Cal has been on the stage and everything.”

And despite the omni-present online dating culture, Harland reveals their paths crossed quite naturally – and quite literally.

“We met on the street in London five years ago – just by Sloane Square, and neither of us knew we were actors,” she says. “I always feel really annoying when I answer that question because we genuinely met on the street. It’s mad.”

However, Harland believes fate would have brought them together eventually anyway.

“My boyfriend actually lived with Dylan [Llewellyn] – the ‘wee English fella’ that’s in Derry Girls when they were younger, and first started off in Hollyoaks.

“So we probably would have been introduced at some point.”

The National Theatre at the South Bank in London. Photo: Yui Mok/PA

Speaking of Derry Girls, it’s no secret there was widespread dismay when the series came to an end last year – but is it possible there could be a comeback?

“No way,” Harland exclaims. “I think [writer] Lisa [McGee] wanted to end it on the Good Friday Agreement, and she wrapped it up well. It was a true story really, so there is no need to add to it.”

With some musicals now banning the audience from singing along Harland has conflicted feelings on the matter.

“Whenever I’m performing, I can’t hear anything other than just the thoughts in my head, but whenever I’m an audience watcher, I’m the first person to turn and give someone a dirty look if they’re unzipping their bag,” she says.