Your first year as a mom can feel like one continuous interrogation of your baby's doctor, your friends, and your own mom for the answers to your parenting questions. Here's a shortcut: In the hopes that I can give some peace of mind, I've answered a bunch of the most common questions I'm asked:

Our 6-month-old just started sitting up, but my friend's baby crawled at that age. Could my child be developmentally delayed?

The timing of motor milestones, especially crawling, varies a lot from baby to baby. Although most begin to crawl (or scoot or slither) sometime between 6 and 9 months, others start as early as 5 and as late as 10 months, or skip crawling altogether. Don't forget: Your baby's progress is more important than her timing. Compare her achievements to what she did a month ago rather than to what your friend's child is doing.

When your baby starts to crawl (and stand and walk) depends in large part on her temperament. By and large, there's no "right" time regarding these stages. Active, wiggly kids (whom I call "motor babies") usually reach these milestones sooner than more mellow types. I've also found that a baby's body can affect how soon she'll get herself off the ground and moving around. In my experience tall, slim babies (whom I dub "banana" body types) are often on the go more quickly  -- as opposed to the heavier ones ("apples" and "pears").

Contributing editor William Sears, M.D., is a pediatrician, the author of 32 books on childcare, and a dad of eight.

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