I agree with all of you on this thread, but I do still have a degree of sympathy for the OP.
The stories about step parents stepping up to the mark are lovely... and that's great if you are allowed to do that. But many step mums (def. happens more than step dads, as more are NRPs) are between a rock and a hard place: Blasted if they don't appear to care and blasted if they do.
I have two lovely DSDs, with whom I have good relationships. THey have space here and are welcome any time. I also appear to have inherited DSD1's BF who appears to live here too now!!!!! (He's lovely and a good influence, so I'm not really complaining!) BUT>>>>>
Dh and I got married in VEGAS to avoid a wedding here in the UK. THere was simply no solution: Don't invite the DSDs, and I'm a heartless bitch who doesn't accept her DH's former life (Couldn't be further from the truth!) or DO invite them, and make them part of the day, and I'm trying to replace their mum and putting them in the middle of a minefield (15 years on, and it's still not civil with ExW). So we decided, and spoke to the kids, that if they weren't there, then no one would be. Seriously, it was me, DH and a couple of strangers.
It feels to me that the OP is feeling pulled in several different directions and doesn't feel quite sure of her position in the whole situation.
I know lots of people say that the kids are difficult because they can 'feel' the OP doesn't want them about. But, I had several years where my DSDs were terribly torn about feelings for their mum and for me. To the point my DSD1 would be unable to eat or relax if she thought her mum was about
. We've all got through it and we're still a family, but it's not always easy and I think the OP was just being honest.