Here are three key things you should know about being a stepmother:
First, it's very hard to be a stepmother.
Second, it's really, really difficult.
Finally, it's much harder than anyone can possibly anticipate at the time they decider to marry a guy who just happens to have kids who come along as a package deal!
It's a myth that the children and adults will just blend right in and feel comfortable and acknowledged in a new stepfamily. Stepfamilies are complex on every front-historically, emotionally, logistically, financially, practically, you name it.
The potential for competition, jealousy, loyalty conflicts and the creation of "outsiders" within and between households is built into the system.
Even the term stepmother is loaded with false assumptions. Nobody can walk into a family that has a history of its own, which did not include her, and become an instant mother.
Don't assume that your stepchildren are looking for another mother. Most children want a friendly relationship of some sort, like an aunt or uncle, a basketball coach, a godmother, or a special pal. No one ever replaces a parent.
Don't push for closeness. Forget your well-intentioned plans to get close form one big happy family. It takes time. Teens are especially confused by demands that they deal with new family members because they are trying to separate from the ones they already have.
Do realize that eldest daughters are their mother's loyal torchbearers and thus become the stepmother's greatest provocateur. In addition to being protective of their mothers, they may also have enjoyed a special position of caretaker with their divorced dad. If you're stepping into a family that includes his teenage daughter, reduce your expectations for closeness to near zero.
McGoldrick puts it this way. If your stepkids are young, or if you're very lucky, you may develop a parent-like relationship over time. If this happens it's a wonderful "extra"-not a given and not something to be expected.
All that should be expected is that stepmothers and stepchildren treat each other with courtesy and respect. It is the parent (not the stepparent) who has the responsibility to see that this important expectation is enforced.
If being a stepmother puts you on the edge of a nervous breakdown, don't think it's your fault. Stepmothers labor under expectations that no mortal can live up. For more help on the subject, see my book, The Mother Dance.