Congrats I guess for finding out you have a relative. I guess it's a dichotomy eh? Exciting yet scary, amongst other things.
TBH, I don't know what you're supposed to think. But IMO, just because you're blood related doesn't mean you have significant obligations to them. Maybe I'm just a little cynical after reading that other thread a few months back about the poster whose relatives left a mess in his basement.
Not sure you want the advice, but IMO if I were you, I'd start the conversation and expectations no differently than if you were hoping to meet a neighbor for the first time. That way, you don't let titles/"family" muddy or confuse the situation. Whatever you'd do for a new neighbor, do for this sister. Go further if you'd like once the ice is broken, but following the same rules you would for someone you'd want to start a friendship with is IMO the easiest way to figure things out without going too quickly or slowly.
Not at all the same situation, but my brother and I started interacting with a 2nd cousin about two to three years ago. She came to visit and since she was technically a relative, we sorta went a little overboard in entertaining her to the point we almost got sick of her after her visit (didn't help she was more than happy to take us up on offers we shouldn't have offered). However, once we started doing what we'd do for any other out of town friend, things were fine for her second visit. It's definitely cool to share about our side of the family to her and vice versa though (long story short, our grandparents had a falling out, but our parents and us cousins are fine with one another).
Congrats. I hope more exciting things unfold with you and your sister.
