<human>: Can you condense the text into three sentences or less?

Hello, another question. I trust Reddit on cat information.

I'm planning on adopting a new cat this Friday, because my 10.5-month old needs a friend. I'm planning on getting someone a little older than her. Do I need to make sure to get separate food for him? My current kitty is pretty much done growing at this point, and has started eating less (I fill her bowl up twice a day and she hasn't finished it in 30 minutes anymore), so I was wondering if I could start the switch to adult food yet. Or, could I feed a 12-15 month old kitten food for a couple months? I can afford getting separate food, but it would be nice if I could use the same.
<bot>: getting a new cat, hopefully not a kitten. Could I use the same food with my 10.5-month-old as a more adult cat? Either switch the current one to adult food or give the newbie kitten food.