How do i welcome my new adopted sister home?

Well for starters don't force yourself on her. You are basically a stranger to her and she is going to be frightened. She will need time to get to know you. Talk to her, ask her about things she likes, but don't be all lovey and trying to hug her and stuff. How would you feel if a complete stranger came up to you and started kissing & hugging on you? It would probably freak you out right? Put yourself in her shoes...she has a huge adjustment to go through. Don't rush it.