Q. How many hours a day should my 6-month-old sleep? Now she takes only two three-minute naps a day, and wakes up a lot at night.

A. Is she energetic, playful, and happy when she's awake? Is she eating and drinking normally? If so, she's probably napping enough.The average amount of sleep a 6-month-old needs is 14 to 15 hours a day (including naps), but that's just an average. I've seen a tremendous range in infant sleep habits in my practice and in my family. My daughter Elsa used to take just two 20-minute catnaps a day at 6 months, gave up naps entirely before a year, and woke us up all the time at night, but it didn't slow her down one bit. We called her the Energizer Bunny Baby.

Separation anxiety often surfaces at 6 months, so it's not uncommon for babies that age to sleep fitfully; they like to check in frequently with Mommy and Daddy, even in the middle of the night. If that's what's going on, your daughter's sleep should improve over the next few months.

Illness can also cause sleep difficulties. Call your doctor if your baby:

• has a fever or other signs of being sick, like cough, vomiting, diarrhea, rash, or pulling on her ears (a possible sign of an ear infection)
• is frequently cranky
• has a poor appetite
• is sleepier than usual.

Chances are, though, she's just fine and is getting the shut-eye she needs.