Not much to look forward to
I was at an out of state wedding last week. My husband was in the wedding and I didn't know anyone, so the groom's family took me under their wing. I spent a lot of time with the step-mom. The mom wasn't in the picture-not sure if she passed away or left.
Anyways, it was very sad to see this step-mom. She seemed like a respectable woman. She has a grown step-son (the groom), and two grown step-daughters, one with a family of her own. They all acted "normal". They seemed to get along okay. But then the step-mom started telling me how one step-daughter criticized her for the dress she was wearing (I thought she looked nice). Then the step-grandchild told her "I don't have to listen to you, you're just an old lady". I felt so bad for her. She started disengaging after that. This lady acted like she was reaching out for anyone that understood and could comfort her. I was sad, not just for her, but because I don't want to be 50+ and still having step issues!
I did notice she acted a little "cold" at times, which could make the steps dislike her. But what starts first? I'm sure she was likely ignored or came "2nd" enough that resentment grew, thus making it easy to be a bit critical (she was a little tough on the step-grandkids). It seems we just have to bend and sway and forget about ourselves to keep the peace. Once we stand up for "us", we became "bitches" in the eyes of the steps.
And apparently in yours 50's...you are STILL dealing with steps 
Yes, I'm "cold" toward my
Yes, I'm "cold" toward my skid, too. I'm a good, happy person in all other ways, though; just not when it comes to putting up with drama from a grown-ass man who expects hand outs.
Anyone seeing me with SD
Anyone seeing me with SD would think I am also cold. Anyone seeing me with anyone else would think I am a warm, compassionate individual.
I am cool towards my SS8. I
I am cool towards my SS8. I did not start this way. I'd dated Men with kids and it's been fine. I also co-parented with my daughters father and his wife so Step-Family was not new to me. For 18yrs we all got along pretty well, everyone knew their role, respected their boundaries. So I naively thought this situation would be okay too. But now there's a lot of resentment over the whole situation. Back at the beginning before I even met SS8, I had my plans to make a connection. I'd ask about him to learn what he likes, what kind of kid he is, etc. I wasn't going to be all fake-can't stand that- but I was going to make an effort and I was kind of excited. Then I met him and immediately realized he was not my DH actual biological child! DH considers him his so never mentioned this to me before. I'd only seen one picture of him from when he was a baby so when he showed up a totally different race and not bi-racial as I expected, I was thrown off. Okay, okay, recovered from that and then learned the story. But it surely made it harder to see him as DH child which impacted my ability to bond to him. Looks nothing like him, acts nothing like him. He was just a random kid to me, like a neighbors kid. Figured I could deal with it and still treated him well, made effort to bond, to care about him as I do any child. But over the years the situation is growing very tense due to how DH and BM co-parents. I've been 3rd in DH life for too long so I'm not only disengaging from kid but from him. So resentment and cooling is usually after the fact from what I can tell.
Age is irrelevant in the
Age is irrelevant in the step-mom world. You can wish to be done with step-parenting issues prior to turning some particular age, but have you not been reading the posts from SMs who are more "mature" and dealing with ADULT skids & all the bullshit that comes with that? Maybe I'm a bit sensitive to the age issue since today's my birthday and I am "mature" and still dealing with this shit.