yes, you can clone a clone... it is better that the previous iteration is well established before trying to do so.
As long as you keep it healthy, can take clonen of clone of clone of clone... while an older plant exhibits asymmetrical growth at some point, which can cause a very slightly lower yield, and even that i am not certain, it should be of the same quality each time. a clone is always as old as the original plant. The age of the plant is more of a concern... end up with hardened ovules at some point and that makes for no good weed.