If the kitten is just nibbling a bit on the TP roll (or anything else), I'd say it's probably okay. If she starts eating it or leaving bits of it around that the other kitten starts eating, I'd take it away. My cats aren't chewers; they mostly just lick and chase things around. The kitten loves edaname pods so much that we call them her "Eddies." She also likes lettuce. She's a strange one, that kitten.

I'm actually jealous of you right now. Kittens (and cats) are just so much fun. To have two would be a blast!