Hello! I was wondering which feline/cat Pokémon would be ideal for a pet? I also have a Ralts (female) and a female Rowlet if it factors in any. I work from home and have a pretty sizeable back garden. Oh! And I live in Kanto.

Pretty much all of them, short of perhaps Mew and Mewtwo (not that you would be able to keep one of either to begin with). However, if you want a local pokémon, meowth are easy to find in Kanto. I would warn you against evolving it considering your ralts, though. Persian can be rather fickle and rough, and ralts tend to be delicate.

If you can import pokémon, or if your local shelter hosts a wider variety of pokémon than usual, the best you can possibly get are members of the skitty and espurr lines, as these have more easy-going personalities, generally speaking. Furthermore, espurr and meowstic would make excellent training partners for both your psychic ralts and your (eventually) ghost rowlet. However, avoid litten and Alolan meowth, partly because they either evolve into or already are dark-types (meaning they won’t mesh well with your pokémon) and partly because Alolan meowth in particular tends to be higher maintenance than other felines.

You may also wish to avoid litleo in general, as you will likely not have a back yard if you keep one. Not because its evolved form would set it on fire but instead because it would be your pyroar’s garden, not yours.

Best of luck!