If you are bringing biological children of your own into the family, you need to prepare them for their new siblings just as you prepared them for their new stepparent. If you have multiple children of your own, they will already have experience with siblings, but if you have one child he may face a greater adjustment and potentially have more fears about the new situation. Hopefully, the children have met their stepsiblings prior to your marriage and have some idea of what to expect. If moving in and marriage haven't happened yet, it is a good idea to take the children out together and start getting them acquainted. Not only will they be able to feel each other out, you and your partner will be able to observe how they will get along. This may help you prepare for any potential problems and identify any commonalities.

Preparing Yourself and Your Biological Children

By nature, you may have more protective feelings toward your biological children. Preparing them for moving in with stepsiblings will also help you prepare for your new stepchildren and any conflicts that may arise between your children and your stepchildren. You know your children better than anyone; try to think of quirky traits or habits they have which may lead to teasing or conflict. If your daughter can't stand the sound of snapping gum or your son doesn't like it when people touch his Star Wars collection, let your partner know about these quirks. Siblings, whether related by blood or marriage, have an uncanny way of quickly figuring out how to push each other's buttons. By figuring out what buttons might be pushed, you can prepare ahead of time for potential conflicts.

Take note of how your biological children push each other's buttons. Do your daughters like to gang up on your son and poke fun at his clothing? Does your son like to invite his friends over and tease your daughter about her childish taste in music? Once your children blend, they may find their stepsiblings can help them gang up on biological siblings or they may use tactics on their stepsiblings that worked effectively with biological siblings. It is important for you and your partner to be aware of these possibilities. Your partner should share the same insights into his children with you.

If There Was an Only Child

If you have an only child, you may find that your child is overwhelmed, anxious, or even angry at the idea of having a sibling. Generally, the younger your child is the less he will be affected by the addition of a stepsibling. However, the older your child the more time he has had to get used to being an only child. Since he doesn't know any differently, it may be tough for him to share you with another child — sharing you with an adult isn't quite as threatening as sharing you with someone who is more his peer. This may make him feel as though he needs to compete for your affection and be the “better,” “nicer,” or “smarter” child. If he doesn't feel as though he is getting enough attention this way, he may become the “bad” child and act out in order to gain more of your attention.

It is really hard for a child to go from being the one and only to a situation where he is one of many or even just one of two. Talk to your child about this and assure him that the two of you will continue to have the bond you have now. Give him ideas on how to get your attention, tell you when he feels neglected, or let you know when he needs more of your time. If he is able to use healthy ways of communicating to you that his needs are not being met, you need to respond to them in a timely and effective manner. At first, he may tell you constantly that you are not spending enough time with him, and he may seem to be monopolizing your time. Be patient and give him extra time. Once he recognizes that he can have your time, he may not feel as anxious about needing your time and will stop asking for it so much. Also, children don't want to hang out with their parents forever, so he will likely outgrow the need to be with you all the time or find friends he would prefer to be with instead of you.

If There Are Multiple Children

Similar to only children, children from multiple-child families may find their family role is threatened or different once they join with their stepsiblings. Your oldest child may no longer be the oldest. Your athletic child may pale in comparison to his stepsibling. Your only girl may now be one of five girls. Feeling as though their status in the family has changed can make children feel very out of control. This is something that is being done to them and not a change they are choosing to make. Helping them see that they still hold an important place in the family even though their status may change should assist in the adjustment. They will always have the role they had before in the eyes of their biological siblings; now they are just taking on new roles in this new family.

You might even suggest that they are taking on bonus roles and point out the benefits of these roles. For example, perhaps your son is the oldest of his biological siblings, but the youngest boy of his stepsiblings. As the oldest, he can role model for his younger siblings, but as the youngest boy in the stepfamily he can inherit all the hand-me-down sports gear and have brothers to look up to and emulate.

As long as your biological children are told, shown, and reminded that you are still there for them whenever they need you, that your love for them hasn't changed, and that they are no less a part of the family now that there are more people in the family, they should feel less anxious about the process. Keep your eye on them and watch for feelings of fear or anxiety, which may be expressed as anger or sadness. If you see the emergence of needy or concerning behaviors, spend time alone with your biological child or children. Do something you used to do together before creating this blended family. Don't lose the special relationship you had as a family and replace it with a new relationship for a new family. Keep the old relationship and use it to help new relationships in your blended family grow.