Jezebella's Crazy Cat Lady Rule is as follows:
If there are more than three furry pets per adult human in a household, that household is a Designated Crazy Cat Lady Zone.
If you're below the limit, you may have another kitten. If above, you may want to seriously reconsider DCCL Zoning. DCCL Zoning often results in everybody in the neighborhood bringing you strays to "find good homes for," and as we all know, the good home we find is usually our own.
I myself, am at maximum feline density prior to rezoning as a DCCL Zone.