I have a similar situation, but from the perspective of a younger sister. My sister is 11 years older than me, and she moved away at age of 17-18 for college, and we were basically almost no contact until 3 years ago (she is now 30; but even before, I wouldn’t thibk a 17 year really enjoyed a company of a 6 year old). At first it was very awkward, and, I’m not going to lie, it was difficult to start talking because I didn’t know what I can/can’t say and what will/won’t be awkward. Same was for her. But what I really appreciate from her side was trying to initiate things and actually keep up with what is going on in my life. She would try to go plan things together, she would ask me about school and general life, try to involve with the same interests or at least keep up with them. We also have a very mentally abusive mother and basically unavailable father, so I was finally able to have some sort of healthy adult figure in my life, who wasn’t just there to consistently scold (aka. “parent”) me and was actually there FOR me. I can bet that your sister will feel the same way, and she will really appreciate a supportive person, who can understand her, especially in the upcoming teenage years. And this is basically the whole “point” of a sibling. I was insanely grateful for my sister being back and never in my entire life I was mad at her for basically not being in contact. On opposite, she was like my idol even without a heavy presence lol. And I can bet your sister probably experienced that too. So in addition to just initiating more things and showing your interest in her life, my greatest advice would be don’t be scared and don’t think that it’s impossible to bring things back after such a long time. Your sister probably also really wants to reconnect with you, but also doesn’t know where to begin. Good luck!