@thegardenvsw second, this hypothesis would account for its exceptional and consistent blooming propensity. While I regard this line of reasoning as tenuous, it nonetheless furnishes a plausible lead regarding the identity of its unknown parent.
If you haven't already done it, here is a reminder to cut back any nepeta that's planted near your roses and has finished flowering ✂️
Doing so will encourage it to produce more flowers, which should tie in nicely with the next flush of rose blooms. 🌹