Sirk serves as adjutant to Commander Socrat Teles within the Galveston Royal Guard. Following Teles' house arrest in episode 47, a guerrilla faction seeking to overthrow Emperor Corsair abducts her. They recruit Sirk to their cause, leading her to collaborate with them to secure Teles' freedom. After assassins kill Teles in episode 52, the surviving Dairugger team members urge her to inherit Teles' vision and lead the effort to rebuild Galveston civilization.

In the original continuity, Sirk is a high-ranking servant in Teles' father's household, not a relative. Unlike her Voltron counterpart Dorma, she fails to persuade Teles to leave Galveston before its destruction. After the planet collapses, she assumes command of the surviving Galveston people during their search for a new homeworld.

The character shares her name and blue-hued skin with the tragic first love of Marvel Comics' Sub-Mariner. Her narrative role parallels that of Erika from *Daimos*, focusing on an alien woman whose brother pursues Earth's invasion while she advocates for peace with humanity.