My husband's 7-year-old daughter has been spending a lot of time in our home lately. We have a three-year-old daughter who has been acting out so much lately. Her anger is mainly focused at me. She back talks and doesn't respond when I talk with her and often covers her ears. She argues with the seven-year-old and I find myself constantly in the middle of screaming matches between the two of them. I try to be fair in resolving the issues, however my three-year-old has often ended arguments with telling her seven-year-old sister that "I am her mommy only, not yours." I know this hurts the seven-year-old. What can I do to stop this? Also, could my 3-year-old be acting out because she feels like her "space" is being invaded by another child? I don't want our three-year-old to feel like she is being invaded and I also want to make the seven-year-old feel welcomed and loved. I need help.

Combining families is challenging, for children and for adults. Your three-year-old daughter's behavior is governed by a number of factors, including her age and development (three is the time in a toddler's life when they develop "initiative" and are prone to be a bit defiant by nature), her own temperament and personality, and your family situation. Just about all three-year-olds who are used to being "queen of the castle" and find their reign suddenly ended by an invader, whether it's a new baby or an older step-sibling, will demonstrate their confusion in the only way they know: with their behavior.

I believe you would find "Positive Discipine for Your Stepfamily: Nurturing Harmony, Respect, and Joy in Your New Family" (Nelsen, Erwin, and Glenn, Prima 2000) Positive Discipline for Step Families very helpful. For the moment, it may help to understand your daughter's behavior from her perspective. The primary human need is for a sense of belonging and significance. It's not hard to see that the sudden presence of an older sister can call a child's sense of belonging into question. Misbehavior is usually a child's way of telling us she is discouraged and doesn't feel she belongs. Understanding this (and the fact that "not listening" is pretty common among three-year-olds anyway) will help you respond with kindness and firmness.

It might help to spend "special time" alone with your three-year-old, and to encourage your husband to do the same. You should also spend "special time" with the seven-year-old, who also needs to feel belonging and significance. You don't have to do anything extravagant: just "hanging out," reading a story, or going for a walk together will do. But the message is "you're important to me." In "Positive Discipline for Your Stepfamily" you will find a story about a family who adds a new baby, and a demonstration using candles that allows children to see that their parents' love is not a limited quantity--there truly is enough for everyone. It will take time and patience, but both girls can learn that they have a special place with you--and to respond to boundaries and each other with respect and cooperation.

Best wishes to you and your family,

Cheryl L. Erwin, MA, MFT
Certified Positive Discipline Associate