It's not all bad
.
There will always be challenges - the main one for me being the things I wouldn't put up with from my own kids or really shouldn't still be the case at their ages but it's just not in my remit to change in the way it would be if I were their parent.
That frustrates me, and one of the main things is what you've picked up on in your post - SCs not doing things for themselves when they are perfectly capable. I know when I have my own children, I'd be encouraging them to do things themselves to foster independence but there is only so much I can do with my SCs and it does impact our household when they are being catered to as if they are 2 years old (parent sitting by their bed until they fall asleep etc). Other frustrations are finances, in-laws clinging onto the ex and making her part of every conversation, ex being a bit of a clingy mum which then makes her children clingy and needy in turn, all plans for Christmas etc revolving around these children, which then impacts time with your own family. All of this is not easy to live with.
But then there are lots of positives too. I have a really lovely relationship with both my SCs and, after having known them for almost 5 years now, they have both fully accepted me as part of their unit with their dad. It's lovely when they draw pictures nowadays and include me! We can all do things together and enjoy it, and I do feel that I've learnt a lot about children from them.
But I did genuinely really struggle in the early days, even before I met them, with the concept of having someone else's children in my life. It's a big thing to adapt to and especially at first it can feel like your life is being controlled by these children and their mum, in terms of when you can do things, how much time you get to spend with your DP, how much holiday he has to take time with you...etc etc. It was a real challenge for me, but I found that as I got to know them better and my DP and I found our feet more, we managed to sort things out together and just make it work. I can see why it doesn't for many but I think if you're both - and that includes the parent! - receptive and willing to compromise then it genuinely can be OK.