Dame Judi Dench told a "really dirty joke" to put Isla Fisher at ease

Isla said: “I had to film two really big scenes with her and I kept saying to myself, ‘Fisher, don’t you forget your lines!'

“And it was almost like she picked up on that energy, and she made a really funny dirty joke that put me right at ease. She’s got the most fantastic sense of humour. From that moment on I just relaxed and it was a masterclass, watching Dame Judi Dench perform.”

The 45-year-old star - who has daughters Olive, 13, Elula, 10, and six-year-old son Montgomery with husband Sacha Baron Cohen - and her brood recently returned to her native Australia and the 'Now You See Me' star is much more at ease there than anywhere else in the world.

She said: “I feel like I can be myself in Australia. “I love the people. I love the colours and the sights and the taste and the smells. And there’s something about being home which is just … it feels very magical.

"I miss it so much when I’m away and I have a very Australian sensibility. Whenever I meet another Aussie, I always think, ‘Oh my gosh, we’re twins!’”

Isla is keen for her kids have a "normal childhood" so although she loves talking about motherhood, she won't do so in public.

She told Australia's Marie Claire magazine: “Motherhood is actually my favourite topic, but I keep it private.

“I think all parents are trying to protect their kids, especially in the social media age. I want our children to have a normal childhood – being able to play outside without pressure or scrutiny. All kids have the right to just be kids, and I would never sell a film or magazine by speaking about [mine]."