Not a stepmom yet but...
My fiance has two kids, daughter is 7 and son is 5. We're 24 and 21(me). I have no qualms about becoming a stepmom, but I haven't even met his kids yet. They're currently with their mother in another state. But in 2 years my fiance gets out of the Army and we're moving back to where his kids are and are filing for full custody. One of my biggest concerns is how his kids will react to me. He goes off to Afghanistan for a year at the end of this year, and we're going down to visit the kids before he leaves. Because of the distance (and possibly their mother) I won't be in their lives almost at all until we move. I don't want the kids to think that just because I'm not around when daddy's not around means I'm not trying to be there for them too, but I don't know if I can do anything.
Also, when we move there's going to be a lot of stress on me besides just new kids. He's moving back to his home town, but I won't know anyone, and the terrain is so flat when I'm used to mountains, that it'll be hard to balance all that and children and the mother and I don't know if he'll understand enough to be supportive.
And my final fear comes into play when/if we have our own kids. I've wanted kids since I was 9, a full 5 years before his daughter was even born. I don't know if he'll be as excited as I will be, or if he'll be jaded to it. I've suffered from post-pardum depression from a lost pregnancy before, so I'll be prone to it. I'm afraid he'll think I'm over reacting. I'm half expecting something like "It's only a child, I did it when I was 16, don't worry about it." and him just blowing off my concerns and not being supportive.
And I'm afraid to talk to him about it because this is all so far into the future. I know I shouldn't be so concerned now, but it's all so much a part of my dreams for my life that I can't help it. Am I just overthinking everything?