Marina Prior (born 18 October 1963) is an Australian soprano and actress with a career mainly in musical theatre. From 1990 to 1993, she starred as the original Christine Daaé in the Australian premiere of "The Phantom of the Opera", opposite Anthony Warlow and later Rob Guest.
Prior has been in a play
This is correct because the paragraph says she has been in theatre. I think the system has a problem with synonyms