Our 22-month-old middle daughter is definitely getting out of control. She's biting us and her big sister, knocking the glasses off of her big sister, and getting too rough with her 3-month-old little sister. We have a small house and she shares a room with her older sister, so it's hard to lock her away when she misbehaves, and time-outs (or "the thinking chair") are definitely not helping, even though she'll sit there until we tell her. Is she too young for the ticket system? If not, what do we do with her when she's lost her tickets for the day? I've been searching the Q&A and the editorials, but have not found any answers. Please help.