While middle school (usually defined as age is an in-between phase in a child's life, it does not make it any less important. Knowing what to look for in your child's development will continue to aid in their wellness. One day He’s as responsible and cooperative as an adult; the next day he’s more like a 7 year-old. Planning beyond today’s basketball game or sleep over party is hard. One minute she’s sunny and enthusiastic. The next she’s gloomy and silent. These pre-teens are in process; they’re becoming more self-sufficient.