I never noticed before that our daughter Brooklynn, who is three years old, wanted so much attention, because she was the only child. But when Mia was born, it became clear that Brooklynn thought she had the run of the house. And she did. She wasn't used to the word no and that was our fault. I know that.

With Brooklynn, we never followed a set routine. Instead we fit her into our routine. If we wanted to watch a show at night and she wanted to stay up, she could. And she still sleeps in our bed. Now I think I should have put her in her own room before the baby came. But at the same time, I like having her in bed with us. I like that we're all together.

About two months after Mia arrived, Brooklynn started having meltdowns — screaming, hitting, kicking and yelling — if she didn't get what she wanted. I couldn't believe it. She's a really wonderful girl.

Often it happened at bedtime. I had a very bad day a while back when she did it twice to me — once at Costco and once at Loblaws. But before that she had waited with me at the doctor's office for an hour and was as good as gold. She's such a good girl. It was hard to believe she could have these fits.

She also had a pretty busy agenda, which was another problem. She was taking ballet, gymnastics and swimming and going to Montessori school. I put her into lots of activities because I felt guilty about Mia taking time away from Brooklynn and thought she had to have lots to do to keep her busy. But it was too much for her and for me. We were constantly rushing.

I was busy and felt guilty. I knew that when I lost my temper or didn't know how to deal with her, it was because I was tired or I hadn't eaten. I was emotional. Then one time I smacked her on the bottom and it really upset me. I was turning into a mother I didn't want to be.

I talked to Dr. Cathryn Tobin, a pediatrician, and she said that Brooklynn was reacting to having a new sibling. I didn't realize it was connected because she was never upset with Mia. She's loving to Mia. Dr. Tobin said it would help Brooklynn to know our structure, and she needed a routine. She said to watch for when she is getting tired, bored or hungry and try to intervene before she has a meltdown. So now if I have to go shopping with Brooklynn, I'll do one thing, not three, and if it's a school day, I won't take her with me. She's only taking swimming classes now; the other classes have finished, and we didn't re-register. I now notice when she's tired or needs a nap — I'm more in tune with her. And when I make her lunch, I also make myself something to eat. I'm no longer getting mad at her because I'm hungry.

Now at bedtime, there's a routine. Maybe not always a bath, but books, then bed. Now that she's getting into more of a routine, she's falliing asleep faster and easier. We'll let her fall asleep in our bed then move her. And my husband, Joe, and I have more time in the evening now. We actually watched a movie together and had a glass of wine.

Now if I say no to something, I basically stick to it. We went to swimming lessons a couple of nights ago, and Brooklynn wanted to take some money out of the tray in the van to buy a treat. She wouldn't put it back, so I looked her straight in the eye and said, "Brooklynn, Mommy said no and when Mommy says no, she means it." She put the money back and we went to class.

Joe and I are following the same routine with Brooklynn rather than having our own routines. And we're letting each other know what we've told her so we're both saying the same thing to her.

I'm working on using a calm voice. What doesn't work is yelling and getting overheated. And that one spanking didn't work; I felt so guilty about it, and it just made her more upset. My goal is not to make her afraid of me or to be an ogre, but to let her know that as much as I love her, I am still the authority.

Brooklynn isn't having as many meltdowns. Now we have many more good moments than bad moments. There are certainly things with Brooklynn that I've learned that I have to change with Mia. Discipline is hard work. It's easier to give in, but I'm sticking to my guns.

Jealousy is a normal response to the arrival of a new baby, and a structured schedule may be the key to a happy household.

Tips from Dr. Cathryn Tobin, pediatrician and mother of four.

Tip 1. Parents should think of discipline as guidance, not punishment. If you decided to take up golf and the golf instructor yelled, threatened or lectured you with every bad stroke and never taught you what a good stroke looks like, chances are you'd feel discouraged and simply give up the sport. Well, kids are the same way. Children need to know what good behaviour looks like; so the next time your child's behaviour causes you grief, before you say a word, pause and ask yourself, "How can I use this situation to teach my child something positive?" Misbehaviour is a great deal less frustrating when you look at it as a learning opportunity.

Tip 2. Children need to hear the word no in order to accept it. Although it is often easier to cave in, it is not in your child's best interest to do so. When your little guy or gal won't take no for an answer, use a firm but neutral voice, and say something like, "I know you're disappointed, but no means no." Then, don't rub it in, and don't feel you need to justify yourself; just move on.

Tip 3. Kids communicate through their behaviour. The little gal isn't going to say, "Hey Mom, I'm really tired. I think I'll go to bed." Instead, she'll pitch a fit, act hyper or whine. A youngster's behaviour tells us what her words can't yet express. Parents often react to a child's misbehaviour and overlook the underlying cause. But when you hang back and think about what's going on, you are bound to find changes you can make that minimize misbehaviour without you having to say a word to the child. For instance, tantrums can often be avoided by putting a sleepy child to bed earlier.

Tip 4. Sibling rivalry isn't the only emotion a new baby inspires. An older child may feel overwhelmed, confused and frustrated when the world as she knows it suddenly changes. Her behaviour may deteriorate, not from jealousy, but from desperation. With the new baby comes a change in routines, habits and expectations. Creating rituals and maintaining structure helps make life more predictable, which is crucial when everything seems to be spinning out of control. Structure doesn't limit a child; it liberates her.

Tip 5. Remember to let your child know that you've noticed and appreciate her cooperation. Give specific feedback, such as, "Brooklynn, thank you for putting the money back when Mommy says no. You're a good listener."

Tip 6. In my experience, a few choice words spoken in a no-kidding-around tone of voice are far more effective than yelling, time-outs or threats. Loving parents invest enormous amount of energy trying to convince children to behave. However, less talk and more short-and-sweet comments are needed.

Dr. Cathryn Tobin is a pediatrician, trained midwife, mother of four and author of The Parent's Problem Solver (Three Rivers, 2002). She is currently working on her second book about her highly successful methods for preventing infant sleep problems. Go to www.askdrcathryn.com.