Dr. Ari Brown helps three mothers cope with common parenting issues: kids who won't listen, sibling rivalry and the challenges of the "toxic tweens."

"I have two children; my daughter is almost 11, my son is 8. When I ask them to do things around the house or their homework, they tend to ignore me until I ask them over and over and over until I finally yell at them. They usually act like they don't hear me. A lot of times my son shouts back at me, and I shout back at him. My kids won't listen! Can you please help me?"

Dr. Ari responds: "Let's talk about what the kids are doing: I believe they read the kids' handbook on how to manipulate parents. There are certain strategies in that book, the first being the 'A' factor which is annoy parents until they go crazy and give up. Then there's the guilt trip that works really well with single parents or working moms. Then you have the negotiators: Let's make a deal!

I would suggest having a family meeting. Go home, get dad involved in this. Sit down and make it clear what their responsibilities are and with responsibilities come consequences, but also privileges. The best discipline is natural consequences: If they don't do their homework, they get a bad grade. If they don't set the table, they don't eat dinner. If they don't clean their room and their clothes are on the floor, you'll throw everything away that's left on the floor. But make sure you follow through on the consequences.

Lastly, don't yell. I know it's your gut instinct to want to explode, but the truth is your actions speak louder than words so if you follow through and implement your plan, it will work much more effectively. If you need to move things along and prod them, don't yell because then you're just being a nag. Set a kitchen timer and say, 'You have 10 minutes to finish watching TV and then it's time to start your homework.' The timer has no emotion."

"I have two kids: Melanie, 19 months, and Tyler, age 4. Melanie was born 10 weeks premature and needed a little extra TLC when she got home from the hospital. My son got a little jealous and ever since then he hasn't been very nice to her. At times, Tyler asks me why I'm paying attention to Melanie and none to him. Sometimes, Tyler will walk over and shove Melanie. I'm very nervous about that. Can you please help me stop this sibling rivalry?"

Dr. Ari responds: "First of all, you have to walk in a 4-year-old's shoes and realize he's trying to get attention, any attention. Praise or punishment, it doesn't matter -- it's attention. Also, older children like to defend their turf. Here's what you need to do with him: Catch him being good. Say, 'I really like how you got dressed' or 'I really like how you put your toys away.' You'll be amazed at how much he responds to that.

The next thing is give him special toys he doesn't need to share and give him special one-on-one time so he knows that he's getting your attention and that it's focused on him. Lastly, give him special jobs so that he feels important. If you're trying to get both kids ready in the morning, have him get the cereal out. That's his 'job.' Then you've actually physically separated the two of them and then you can get your 2-year-old ready."

"I have an almost-9-year-old who, since the age of 6, thinks she's 16. She's bossy, and wants to go places by herself without adult supervision. She talks to her sister like she's her mother. Her sister will come to me and ask me a question, and I'll give her my answer, but then Jessica has to comment and pretend she's the mom."

Dr. Ari responds: "You have survived the 'terrible twos' with her and now you're in the 'toxic tweens.' It starts around ages 8-12. Your daughter wants to be independent, in control and she wants to earn your respect. If you give her freedom with healthy boundaries, you will get along. Include her in the conversation you have with her sister. What you're saying is "I value your opinion." That doesn't mean she can parent your other children, it just means that you're listening to her.

Also, think of the rudeness like the temper tantrums when she was a toddler; it's not a form of communication. You either ignore it or you say, 'I can't help you when you're speaking to me like that.' If you don't respond, she'll stop doing it; it no longer is effective. Walk away or ignore it. It's a long road but if you keep the lines of communication open now, it will go a long way when she really is a teen."