A Stepparent's Role
As a stepparent, you may face difficulty fitting into the new family. Since you may be viewed as an "outsider," you may encounter surprisingly stiff resistance to your inclusion in the family, in the form of unexpectedly powerful and negative feelings such as jealousy and resentment, as well as your own confusion and sense of inadequacy. Your role in the family, especially early on, is ill-defined and you may end up trying out several different roles before finding one that "fits." While this lack of definition can be stressful and confusing, it also gives you the freedom and latitude to determine a role all your own.
Duncan, Stephen F., "A Stepparent's Role" (2019). Forever Families. 80.