Stepfamily Realities 22-24 - Equal Love
Many well-meaning stepparents and relatives, specially some religiously-devout people, believe "New stepparents should (immediately) care about their stepchild/ren as much as their own." Even if they entered the picture when their stepchild was, say, under six years old, many stepparents feel guilty about favoring their own kids, nieces, and nephews at first. This can be specially true if their biokids are teens.
Besides the unique genetic and ancestral ties that unite them, bio-parents have shared life experiences with their own children for years. They've usually spent much less time with their stepchild/ren. To discern your reality, answer this honestly: "If our house was burning, which kids would you or I save first?" Usually blood is thicker than water! A rose doesn't have to apologize for not being an orchid...
Typical stepparents and stepkin may genuinely feel equal concern for biological and step kids, after a long (e.g. five or more years) pre-re/marriage friendship or custodial stepfamily history. Otherwise, the reality to accept without guilt is: "I love my own kids more (or differently) than yours so far, and that's natural and OK!" Incidentally, if a stepparent is childless, the birth of an "ours" child may activate this "mandatory fairness" myth well after re/wedding!