Can Caitlyn's ability only be used during your turn when she is ready at a battlefield and the opponent has a unit on the other battlefield, with no showdown or chain happening?

Ruling: Caitlyn's ability can only be used on your turn when she is ready at a battlefield, the opponent has a unit on the other battlefield, and no showdown or chain is happening.

Nuances:

• All conditions must be met simultaneously: it must be your turn, Caitlyn must be ready at a battlefield, an opponent unit must be at the other battlefield, and no showdown or chain can be in progress.