AITA for telling my sister we were strangers after she eloped and broke all contact with us years ago?

Apologies in advance if this post seems disorganized, my head is still reeling from all this. 9 years ago ( I was 18 then) my older sister eloped with her then boyfriend. Our parents (we're an immigrant family) were vehemently opposed to her relationship, I remember me being ok with it personally, it wasn't my place. She eloped with her boyfriend and cut of all contact with us. My parents were besides themselves. I tried reaching out to her back then on different platforms but was blocked. I even reached out to her best friends and asked them if they could at least get me in touch with her, they said she didn't know where she lived now, but that she'd told them she was happy. She had also left her workplace. Eventually we all (me and my parents) came to like an unspoken agreement to pretend she was never here, and I blocked her everywhere too. I remember being extra particular to call regularly when I was in college because I was worried about their state of mind. We're now at a place where I can't remember the last time she crossed our minds.

Yesterday my sister knocked on my apartment door. She cried and hugged me when she saw me, I hugged her back initially too, I wasn't really thinking at the time. She was just going on about how much I had changed, how much she'd missed me all these years. Eventually I kind of remembered everything, and asked her why she was here, and who had given her my address. She said she had swore to them that she wouldnt tell. I asked her why didn't she call first since whoever gave my address probably gave my number too, she said she just wanted to see me in person. I told her we'd gotten over her, why was she here. She said her issue had only been with our parents, not me, I told her about how I'd been blocked too by her when she left. She told me she was sorry she'd hurt me, but she had wanted a fresh start, told me I was an uncle to a nephew and a niece (they weren't there at the time, they were at their father's, they recently divorced). She acted surprised that I wouldn't know, said she'd told someone to tell our parents about them.

Maybe it was hearing about the divorce that furstrated me more, because if we were going to have gone through all this pain, at least she could've found lasting happiness, I just told her she was a stranger to me now. She said we could have lunch together she wanted to know all about what I'd been up to, I told her it was best if we continued to have no contact, she didn't act like an older sister when I needed her to, and that we were no longer family, we'd mourned her already and we were now strangers. She was tearful, she gave me her address and phone number and left.

Last night, I spoke to my girlfriend about what had happened. She said she was still my sister, that I shouldn't have just turned her away. I told her she didnt know what we'd gone through in the days after she had eloped. But I still wanted to know here AITA?