Where to Start??

Hello! This is my very first post on this site. Recently, my half sister was found! Our relatives searched for her. My mother gave her up for adoption, she was 19 and unmarried. Then my mother got married to my father several years later, and had 3 children together with him. I am the oldest of the 3. Where to start? Scince my family found her, we have only had email contact, and a few phone conversations. She left for a 3 week vacation only a few days after we learned she was found. And so we are still trying to arrange a meeting. I have known about this "sister" scince I was a young girl and my grandmother thought it was time my sister and I knew of this baby my mother had before we were born. All my life my mother held onto a small poloroid photo of this baby, wrapped in a hand knit blanket my grandmother made for this baby. We have long talked about her, wondered about her, and hoped she was ok. We had made many attempts to begin the long search process, but it seems my relatives found the "right needles in the right haystacks" and somehow..they found her! So, now, faced with the reality of a living human with feelings and a aching heart for my mother...it is so much more than I ever dreamed. From our initial conversation she asked me what should she call my mother, "mom or by her first name". I told her I though my mother would probably want to show repect for her MOTHER who raised her. That was dismissed as not too important, as she was distanced from her adoptive mother. Now I am in the middle, dealing with mom who is struggling with disbelief that the baby in the picture is really this adult woman, wanting to call her "mom". Overwhelming...and then she is now dealing with the flood of bad memories connected with that time in her life. How she made her parents feel, the pain of it all...it is all coming flooding back to her. Then there is this woman, who is a stranger to us, that is wanting this to go so much faster than we are wanting to go. And I am afraid we are a big dissapointment to her so far. She probably has waited all her life for this, and now that it is here...she might wish real life was more like how she dreamt it would be. So we are trying to set up a reunion visit. How do I help this to go smoothly, and be the best experience for the two of them?? This is all so much more emotion than any of us anticipated! I feel totally without any clue as to what I am doing with this. I want to try to put myself in my new sister's shoes...and have been trying to think about how she must feel, but I really have no clue. I think my mom has not really avidly searched for this daughter, mostly due to fear of rejection. And now, she is faced with a woman who is wanting to call her mom...wow! It is a little to fast. Any tips, suggestions?? I am brand new in my search for answers in reuniting with her. My mother and her daugher are so fragile right now. I need help to treat them both with TLC~~~ Thanks!