Giving step children the space they need
Your step children are like all children, they need space to breathe. They probably find it's hard enough having one overprotective mom, they don't need another one. The bigger they are, the more right they have to claim a bit of personal space.
However, not interfering doesn't equate to complete indifference. Try to strike a balance so that you don't hear the venomous phrase feared by all step moms across the world: "You're not my mom anyway!".
Expert's advice: "The most fulfilled step moms are those who live their lives! In other words, those who have personal activities and hobbies, those who are independent and don't feel like they're on a mission with regards to their step children, those who give themselves space and who manage to invest emotionally without investing themselves entirely! Easy, right?"