I haven't had a kitten in years. Mimi was six weeks old when I got her and she was quite playful as I remember. But I never had to shut her up. Maybe closing her in the bathroom is making her more "kitten like" than she would be if you gave her some freedom. I know I'd go bonkers if I were locked in a bathroom 24/7, and I can guarantee that any of my pets would. Blueberry can certainly handle this little one. Let them play.....can you isolate the kitten in your room instead of the bathroom when you are at school? I think "boredom" is the key here. But if you truly don't think you can handle it, take her back and give her the opportunity to be adopted by a different family who can handle her.

Good luck. Hope I didn't sound too harsh, but a kitten is exactly that and they are adventurous, busy and FUN!!!!!