We were able to get Joey almost two years before his great grandfather died last summer. When our first RR passed away, we were out the next week looking for a puppy. That puppy was Joey's great grandfather. Since then we have been firm believers in finding a new pup (or kitten, in your case) when we lose one.
For us, it helps the healing process, which is still ongoing. Like your Rocket, our dear old boy was very special.
