A beautiful freighter captain, in 2371, Kasidy met her future husband, Benjamin Sisko, during a stop-over at Deep Space Nine. Yates and Sisko's relationship weathered both Yates' six-month stay in prison and the Dominion-Federation war.

In 2375, Yates became pregnant and, despite warnings from the Prophets, married Sisko. Shortly thereafter, Yates was essentially widowed, as her husband joined the Prophets in another reality for an indeterminate amount of time.