Q&A: My 10-month-old is not very mobile. Should I worry?

There are three key factors that combine to allow normal development, and, when development isn't normal, it's often possible to pinpoint the problem to one of those three areas. They are: innate ability, temperament and environment.

What you describe is unusual development. Infants are usually working very hard for toys that are out of reach by 6 to 7 months, and are rolling both ways before 10 months.

What I cannot tell you, though, is if this is a reflection of her personality—some children are content with what they have and don't reach hard for something else—or the skills of her muscles and nerves. It's also possible that you may be describing an infant with weak upper body muscles.

You do need to know. My advice is to bring your daughter to her pediatrician, describe what she is and is not doing, and request a thorough developmental assessment. This will give you the information you really need to understand whether or not this is a problem.