Bringing a new baby into the home is a big adjustment for everyone, but it can be especially difficult for a 3-year-old who's not yet able to verbally express his feelings. He always seems to want your attention just when the baby has a loaded diaper. It's normal for him to have a hard time, but it's important for you to know what to expect and how to handle trying situations.
Pre-baby, your 3-year-old was all excited about being a big girl, but now that the new baby is here, she longs for the time when she was your baby. You might find that she has more potty accidents, wants to start nursing again or suddenly can't do any number of tasks that she used to be able to do on her own. Forcing her to do certain tasks will probably backfire on you, causing her to be even more stubborn. Instead, do tasks for her when you have to, but praise her when she does things on her own. The more praise she hears -- and the more positive attention she gets -- the more she'll want to do things. Sometimes, though, you can also baby her, by holding her and rocking her in your arms, for example.
When little ones can't express their feelings, they often erupt into a giant tantrum. This can happen at any time, but it seems that it's most likely to happen just as you put the baby down for a nap. Remember that children who are tired or hungry throw tantrums, so you may be able to head those off by sticking to your 3-year-old's nap and eating schedule, even if it means letting the baby cry for a few minutes.
Though common, aggression in a toddler after a new baby comes is particularly hard to deal with. You'll have to keep an eye on the baby at all times to make sure he's not in danger. This often happens because the older child has learned that a hit, kick or push is a surefire way to get the attention he wants. When your 3-year-old starts getting aggressive, stay calm, get down on his level, look him in the eye and say, "Hands are not for hitting." Sometimes, simply hugging your child when he's aggressive can help his negative energy dissipate. Spend more "alone time" with the toddler and you might see a reduction in aggressive behavior.
What goes into her mouth is one of the only things that your 3-year-old has some control over, so she may use this to show her displeasure with the new baby. She might become picky, not eat at all or even start eating a lot more. Encourage healthy eating, but do allow her some choices, to avoid battles. For example, you may not want to allow her to choose between eating or not eating, but you might ask, "Would you like an apple or a banana with your sandwich?"