As a 16-year-old longing for a career on the stage, Jenna Lee James left behind her Clydebank home for life in London with barely a backward glance. Little knowing that years later, she would know exactly how her parents felt.

Playing the role of Donna in the hit stage musical Mamma Mia!, James goes through the heartbreak of separation each time her on-stage daughter Sophie gets ready to marry boyfriend Sky. And thinking about the folks back home is how she brings a sense of honesty and truthfulness to the role.

'I'm away from my mum all the time,' says James. 'She's up in Scotland and I'm down in London, and I miss her. So when I connect with my daughter on stage, as Donna, I think about my own mother.

'And there have been a couple of times when my mum has actually been sitting in the audience, and when Sophie walks away from me on stage, I think now I know how my mum felt when I was 16 and left home to move to London.'

Nowhere does this hit home more than during 'Slipping Through My Fingers', a little known song from Abba's 1981 Arrival album – but a key moment in Mamma Mia!.

'That's the song everybody comments on,' says James. 'And it's strange, because "Slipping Through My Fingers" is now more associated with the show than with Abba, because it wasn't a massive hit for them, but everybody talks about it in Mamma Mia!.

'And whether you're a mum, or thinking about your mum, it's such a poignant moment and so beautifully written in every way. We've had all the fun at the beginning of the show with songs like "Dancing Queen", and then with "Slipping Through My Fingers" and "The Winner Takes it All" you have these very truthful moments that feel very real.'

As a strong vocalist, with shows such as 'We Will Rock You' and 'Tonight's the Night' under her belt, James is well placed to do these big ballads justice. But with this show, she says, it's less about demonstrating her technique and more about connecting with the audience.

'These are fantastic songs to sing,' she says. 'But compared to all the other shows I've done, like We Will Rock You, this is very different. What I've found with Mamma Mia! is I don't focus on how I sing the songs – I focus on how I'm portraying them.

'So rather than thinking "am I going to get that note out, or do that little trill at the end?" – when I sing a song like "The Winner Takes it All", it's not about showing off, it's about telling a story. And if you tell that story well, the notes just happen.'

It's nearly 18 years since the musical first premiered in London, stringing together some of Abba's finest songs to tell the tale of a bride-to-be's quest to find her father. With productions having played all over the world, on Broadway and currently touring the UK, Mamma Mia! shows no signs of slowing down – and much of that success is down to the source material.

'The music is just timeless,' says James. 'You walk into a shop or a club and there's an Abba song playing. They're all so catchy and the lyrics are brilliant.

'There's story within every song from 'Slipping Through My Fingers' to 'Knowing Me, Knowing You', and the way it has all been put together in the show is just so clever. I think that's why it's in its 18th year and I'm sure it will run for many more years to come. People just love it, and by the end of the night, the whole audience is on its feet.'

Mamma Mia!, Edinburgh Playhouse, Tue 29 Nov–Sat 7 Jan 2017.