Laura Donnelly: "The baby cries and the goose poos, but that's what makes The Ferryman magical"

The Royal Court run of The Ferryman sold out in minutes, did that put more pressure on you?
Absolutely, it really added pressure. It sold out so quickly at the Court and nobody knew what it was about. That meant they were putting their trust in Sam [Mendes, director] and Jez [Butterworth, writer], and – while we knew we were in safe hands – sometimes people's expectations are so high that it's difficult to meet them with anything. So we knew we had to bring something special. On the first preview, it was such an immense relief to see people on their feet at the end.

How true is it that it's based on your own personal experiences?
Yeah, that's completely true. My mum's brother, Eugene Simons, disappeared on New Year's Day in 1981. He was murdered by the IRA, the family didn't have any answers about what happened to him. He was discovered by accident in a bog by the border in Ireland, in May 1984. I spoke with Jez about it and he went off and looked further into the stories of the 17 Disappeared in Northern Ireland. So the Seamus storyline in The Ferryman is based on that.

So it must be very personal for you to tell that story each night?
It's made it an incredibly special play to be part of. In a way I get to perform it as a tribute to my family, my mother in particular, and to the families of the Disappeared. It's an incredibly heartbreaking set of stories, what the families went through – and are still going through – is incredibly harrowing. So to be able to bring that to such a large public forum has been quite redemptive, it makes me very proud.

The show portrays this huge Northern Irish family, is that something you recognise from growing up?
Absolutely, the family on stage is quite recognisable to most of us in the cast, we were all able to say 'Aunt Maggie Faraway is exactly like my grandmother'. Everybody had their own stories about the very familiar stories. The characters are so fully realised, so rounded that I think anybody that has Irish blood in them will probably recognise one or two of the characters.

They do say never to work with children or animals, but you have many of both, how has that been?
It has been relatively smooth sailing. You can't tell a baby what to do but we managed to find a few babies that are remarkably calm and just seem to like being on stage, so that's been wonderful. Carla Langley [who plays Sheena] does most of the baby wrangling, and she has some wonderful tricks up her sleeves in case the babies are upset. John Hodgkinson [who plays Tom Kettle] handles most of the animals, he has formed a real relationship with the goose, they get on really well! But equally, the goose will poo on stage and there's nothing we can do about it. I think that's what really makes it magical, for those moments an audience is so aware that they are not watching a performance, they're watching something real and I think that really helps drop you further into the play – all bets are off.

So on the one hand you have this absolute realness, but then that's juxtaposed with the mythical aspects of the play…
It's a characteristic of Jez's writing, he's done that in all his plays that I've seen and been part of, it's one of the things I love about his writing. It seems to work particularly well with an Irish play because Irish culture is full of that anyway. We've always been existing in a midpoint between our politics and an incredible amount of spiritualism and mysticism that goes back as long as the country has existed.

It's Paddy Considine's stage debut, have you been showing him the theatrical ropes?
I guess we all have been to some extent. As far as I'm concerned Paddy is one of the greatest British film actors and I could not have been more excited when I heard he was cast. He came in to the whole process incredibly humble, he just wanted to learn. For the first couple of weeks he just soaked it all in and then as the process went on it just seemed to happen by osmosis. He's been an incredibly generous actor to be on stage with every night.

You went to Broadway with the last Butterworth play you did, The River, is that the hope this time around?
The intention is to take this to Broadway at some point, probably next year. There's nothing set in stone by any means, but it's gone down so well with the audiences here that I think everybody would love that to be the next step. Certainly the cast and company, we're all dying to get out there.

If you could play any person on stage what would it be?
I'd like to play something that is further away from who I am, maybe something that isn't set at home and doesn't necessarily speak to me personally. One of the things I'd love to do next is a Tennessee Williams play, he writes women so beautifully. But actually I think more in terms of writers and directors that I'd like to work with.

Who would that be?
I've loved Robert Icke's work that I've seen recently. In terms of writers, I think Conor McPherson's plays are always beautiful. I'd happily just keep working at the Royal Court for the rest of my life to be honest, the talent that comes through there is always very interesting to watch.

The Ferryman runs at the Gielgud Theatre until 6 January 2018.

Book tickets for The Ferryman