When Sam was an infant, there was no point to laying her down in her crib -- or anywhere else, for that matter -- by herself. She'd be up in 45 minutes. When she was 6 weeks old, she went through a spell where she wouldn't sleep at all unless someone was holding her.

Not Noah. He sleeps as long as nine and a half hours a night right now, then is awake for about an hour, then has a four-hour morning nap, then is awake for another two hours or so, then has a three- to four-hour afternoon nap, then is awake for an hour, then has another two-hour nap around dinnertime, then is awake for about two or three hours, then goes back to bed for the night.

Clearly, I'm so great at this being a mommy thing this time! I mean, why else would he be such an easy baby? (And please, believe me, I'm definitely not complaining about this.)

But his sleeping so much means, of course, that I've got to try to keep a 4-year-old slightly quiet most of the day.

And here we enter the part where I suck big time.

Because she's a kid with a new sibling, Sam's been testing me. A lot. OK, nonstop. That selective-hearing thing that was mildly annoying before has become an every-minute-of-the-day problem. And I feel like I'm on her constantly, with most of my interaction with her consisting of "Sam, don't do that!" and "Samantha! I said don't touch that!" and "Sam! I just told you not to lay on top of the cat, and there you are, laying on top of him again!"

I'm trying very hard to compliment her when I see her doing the things I want her to do, but, right now, positive reinforcement is a much smaller percentage of my speech than it ever has been. And I hate that about myself.

How much of her defiance do I attribute to this being a phase that she'll outgrow, and how much do I really crack down on her? Sometimes I feel like I'm way too hard on her, and other times I feel like nothing I'm doing or saying is making a difference in her behavior. For those of you with two or more kids, how do you handle this?