Kelly originated the role of Mary Poppins in the West End, winning the Olivier for Best Actress in a Musical. She has also appeared in Fiddler on the Roof on Broadway, as well as West End productions of Lord of the Rings, Beauty and the Beast and My Fair Lady.
Pinero's 1893 play centres on Paula, the second wife of the upper class Arthur Tanqueray, who is a 'woman with a past'. But Tanqueray has no idea how that past will catch up with him in the end.
Where did you grow up?
On the Isle of Wight
Where do you live now?
I currently live everywhere. I follow the interesting work and I'm happy with that. I'm so thrilled to be in Kingston - I'm in love with it and will hopefully work here after this play. Fingers crossed.
What made you want to become an actress?
I never really planned ahead to be an actress. I started at the local theatre at 11. I just kept getting excited about doing the next show. I live like that now, I'm always just hoping to do something challenging or fun next.
What else might you have done professionally?
I love history. I think it's why I love stories so much. I love learning about what life used to be like for people in different generations. So maybe if I wasn't an actress I'd go back to school and learn to be a teacher.
Who were your early heroes?
I listened to a lot of Mariah Carey, Whitney Houston and Barbara Streisand growing up, but watching The Sound of Music every day might have had something to do with me wanting to be in movies. Julie Andrews is pretty awesome. It was so lovely to meet her when I played Mary Poppins. I was more nervous about meeting her than anyone else - I think my skirt fell off in "Jolly Holiday" because of it. I was mortified!
First big break?
My first big break job was Beauty and the Beast - I played an enchanted object.
Who are your favourite directors?
Working with Tim Burton was one of the most interesting experiences. He works with most of the same team that he has used on other movies so it felt like I was coming to work amongst family. His attention for detail is so inspiring. The set always seemed so calm and fun.
What was the first thing you saw on stage that had a big impact on you?
The first thing I ever saw was the tour of Cats. It took my breath away. My grandma took me. I had the songs engraved on my brain the rest of that week and danced around to the songs in my head. I kept wondering how they got to make trash look so big! I was only eight and it was so magical.
And the last?
It wasn't on stage as such but the most recent performance by an actress that truly inspired me was Emily Blunt in The Young Victoria. She's someone that is really inspiring me to be better.
Do you often get recognised?
I never get recognised - I like it that way!
If you could swap places with one person - living or dead - for a day, who would it be?
I would pick someone living, ha ha. Bruce Parry. He went to live with tribes - that sounds amazing.
What are you reading at the moment?
I am currently reading Pride and Prejudice and Zombies right now - it's fantastic and hilarious. I couldn't believe it when I heard about it! Action, ninjas, period drama and romance. It's so fun.
What's your favourite website?
I'm an Instagram addict. I get to keep up to date with all my friend's lives around the world. I love it. We've got a hash tag for the show - #2ndmrstanqueray - so check it out.
Favourite holiday destination?
My dream holiday destination would definitely be an adventure in Andorra canyoning and mountain biking in the wild terrain - sounds bliss to me!
Do you have any pre-show rituals?
Just staying calm as possible. I stretch a lot, hug everyone and drink lots of water.
Why did you want to get involved with this production?
When I first read The Second Mrs Tanqueray I couldn't put it down, I found it fascinating in terms of language and an interesting social commentary on relationships. I had also heard great things about the Rose theatre. I knew it would be another challenge as I hadn't done a play in a while. So I was glad when I was offered it.
What's your favourite line in the play?
"However I have my revenge. She's six and 40 and wish nothing worse to happen to any woman." The character I play is a little mean spirited at times!
Would you say we're less class obsessed than when the play first appeared?
I think class has turned into something else in our generation. Sadly we know people are still living in absolute poverty even in this country. The class line is less obvious and we are lucky to live in a country that is allowing more freedom and opportunities for everyone regardless of their background or financial position. But there are still so many living in such poor conditions and it's so easy to forget that.
What have you got lined up next?
I'm looking forward to the official release of the musical film we made in Australia. It's called Goddess. It was incredible to make, on location in Tasmania and Sydney.
Which role is top of your wish list?
A role I would love to play is Elizabeth Taylor in a film. I know it's been done but maybe that part will come around later in my life. She was an extraordinary person.