This Female Psi Cop was an associate of Alfred Bester.
In 2260, she came to meet Bester on B5 after finding a Dust dealer. He had been taking Sleepers at the time and lamented that she did not arrive earlier to scan Michael Garibaldi. They discussed how Dust was created by the Psi Corps and that they were glad the confiscated drug was back in their control.
Behind the Scenes
It has been speculated that the Psi Cop portrayed by Judy Levitt is, in fact, the occasionally mentioned wife of Alfred Bester.