Shirna was a Lurman showman.
She traveled with Vorg to Inter Minor by cargo thruster to demonstrate the Scope as part of a show. As they were received with suspicion, she wished that she had never come saying that she should have stayed with the All-star Dance Company, her former employers.
Despite these difficulties, she did help the Doctor get back in and out of the scope to rescue Jo. (DW: Carnival of Monsters)