The iconic show opened at Sydney's Lyric theatre on Tuesday and James performed as the old cat Jennyanydots for two performances on Wednesday.

She usually performs as Olivia and is an understudy for the major role. However, due to illness she temporarily stepped into the role of Jennyanydots and will take over the role permanently when the show opens in Manila on July 24.

"Sydney has been good practice for me," James told The Word. "Jennyanydots is a much older cat and has to perform one of the tap dancing numbers."

Jennyanydots is the large cat who sits around and teaches the mice music and crocheting. The song about her is The Old Gumbie Cat.

James learned tap in Newcastle from the age of five.

Now 26, she has been with Cats for two years. During that time she has performed extensively in Asia, including China and Korea, and throughout Australia.

Sydney is the last Australian capital city for the show and although the production has copped some critical reviews, James said it has been well received by audiences.

"I try not to take too much notice of the reviews," she said.

"It's a well-known musical and people either love it or hate it, but the response in Sydney has been overwhelmingly positive."

While James's stage credits include Fiddler on the Roof, Crazy for You and A Funny Thing Happened on the Way to the Forum, Tuesday was her first musical performance in Sydney.

James attended Merewether High before graduating from the West Australian Academy of Performing Arts, majoring in music theatre, in 2005.