The cat outlived Ripley, because travel time between LV426 and Earth (with Fury 161 inbetween) is only 3 weeks as per the script. The novelizations get some details wrong, maybe because of being based on early drafts or just artistic license. It wasn't years between Aliens and Alien 3. Hell, in the original film, it…

Oh mein gott, it's the Tapioca's Revenge.