How lucky those children are to have you play such an important role in their rearing. It sounds as though your new granddaughter may have what is called ADD—Attention Deficit Disorder. This is just about the most common behavior problem seen in children today. For some reason, it is far more prevalent today than it used to be, and there is not complete agreement about what has precipitated this increase. Some experts think the apparent increase simply indicates that we are better able to recognize the condition, whereas others consider it an inevitable consequence of our more frenetic pace and style of life and too much television.
The first thing I would do is talk to her teacher and find out whether she shows the same kind of behavior at school. (You mention that her schoolwork has suffered, so I assume you have already done that.) Then observe her carefully for a few days and note whether she is able to do better under some conditions than others. For example, note whether the presence or absence of other children has an effect, if she is worse at certain times of day, after eating certain foods, or after watching TV. Then, with this information at hand, schedule a special appointment with her pediatrician, who can evaluate her behavior and tell you if additional tests are desirable. As you have probably read, many children who show this kind of behavior are put on medication, with Ritalin being the drug most often prescribed. Its use, however, is controversial, and there are many heated debates in the scientific literature about its value. Some people feel that such medication may, in the long run, do more harm than good. Finally, be sure to involve her parents in whatever you do. Consistency between what happens at your house and what happens when she is with them is very important.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.