Glad to hear the ratio was way more rational than this article makes it seem.

As soon as the parents apologize for years of attempts at forcing OP to treat Dad's new wife as Mom, then perhaps OP should apologize for saying all of that at Christmas in front of the whole family. But she probably won't get that apology, will she? They've been keeping up this shtick with the poor girl for roughly 4 years! I feel she did what she did partially out of the desire to have witnesses not only to her statement of her boundaries on this issue, but also how her father and new wife typically responded to her. Unfortunately, she did lose control of her emotions and said hurtful things which forestalled whatever Dad and the new wife might have responded with had she been a bit more restrained. The last comment speaks of the love stepmother may have for OP, but I doubt there's much there given her egotistical need to do battle with her stepdaughter for several years(!) over calling her Mom.

"She gives you basic necessities, therefore you're obligated to love her as a parent"

"Nothing in the story makes it sound like the stepmom was really overbearing or "forcing" her into anything." You might want to re-read the article. Just because the step-mom was "nice" about things doesn't mean she wasn't overbearing or forcing OP to do things OP didn't want to do. And what does her sisters being "adults" have to do with the step-mom not even trying to have a relationship with them? That contradicts what you're saying about not forcing anything with OP since the sisters were adults they didn't have to deal with that but since OP was a kid, they do? " If anything it sounds like she was going out of her way to try to show the kid she was still loved and wanted to support her." Yeah, and OP let it be known from the beginning that she didn't want that. So, what, by your opinion OP HAS to reciprocate those feelings because she's a kid and the step-mom was nice? That literally goes against you saying OP wasn;t "forced". You're obviously welcome to feel YTA but come on.

No, I know from my own experience the stepmom could have handled it more gracefully. I (M -- 33 at the time) had never wanted kids. I'd been living with my then-girlfriend (now wife) for less than a year when her ex died and her 15-year-old twin boys abruptly moved in with us. I respected their relationship with their dad and never expected them, then or now, to accept me in that role. I participated in family activities, shared in household chores, was there when the boys or their mom needed me, backed her up when she would set rules for them, etc. I helped teach them to drive, took them to breakfast or on camping trips when their mom had to work, whatever. We were and still are on a first-name basis and I never pretended to be their dad (although I do call them my stepsons). There were rough patches, but we muddled through and are as much family as anyone, even without the titles. Now their kids call me "grandpa" sometimes, which I like, but I've never insisted on that either.