Sleep training isn't easy, but there are ways to make it more tolerable for everyone else in the house. Consider buying a white noise machine for your older kid's room -- the sounds will drown out middle-of-the-night crying. (You can also play a relaxing CD softly on repeat or keep a fan running.) It's also a good idea to talk to your older child about what's going on. Explain that her baby brother is learning how to sleep through the night, and remind her that she knows how to get herself back to sleep when she wakes up. Make a plan together for what she can do if she's awakened. For instance, you could tell her, "Close your eyes again, cuddle with your bear, and think about the story we read right before bedtime."
When your older kid wakes up, don't linger in her bedroom. Go in and explain (in whispers) what's happening: "Your brother is crying because he's having trouble falling back asleep." Don't turn on any lights or do anything that may make her more alert. Let her know what the plan is, and be consistent each time she gets up. You could say, "Mommy is going to tuck you in now and give you a kiss. Then we all have to go to bed until morning."
Above all, be patient. You may have two cranky kids for a while until your youngest is sleeping through the night. When you see more frequent tantrums, whining, or clinginess, you'll know why. Just think how tough it is for you to make it through the day -- and you're a grown-up who can order up a latte! So hang in there, maintain a regular bedtime and naptime for your kids, and someday soon everybody in your home will be sleeping tight.
Originally published in American Baby magazine, March 2004. Updated 2009