I am sorry you are going through this. It can be so hard assimilating a new person into your family. I have been on both sides of this situation. I am very shy and it takes me along time to feel comfortable with new people. Group/family gatherings can be almost painful, until I get to know people. Although I am much, much better than I was in my teens and twenties. My dh has a large, loud group of friends that he considered family. I did not fit in with them, and they did not like that he was changing. So I know how hard it can be, and my dh did not always do what he could to make it easier for anyone. Btw when he changed it was for the better. He quit drinking and partying and became much more focused on our family. The best thing my dh friends and his mother could have done was accept me the way I was and give me time to find my place.
On the other hand we cannot stand my dss1's girlfriend. They have been dating for over a year and he lives with her and parents. She is gradually pulling him away from his friends and family. She is not shy. I wish she was, I get that. We have always welcomed her and I thought we had a good relationship. However she has started trying to cause problems between us and dhs ex-wife. Telling her things that happen here, but only the parts that make me look bad. Really her problem seems to be with me. She doesn't agree with hs and tell my dss's that I don't know what I am doing. When my dss2 was in a car accident she told dss1 that they couldn't come home, we live 3 hrs away, because it would mess up her perfect attendance and put too many miles on her car. Even with all this we have been nice to her and have not said anything to dss, yet. We love him and don't want to alienate him. I am hoping that in time either he will break up with her or she will grow up and realize she does not know everything. Although what I would really love is to pack her in a box and send her to another dimension. Let them deal with her.:lol:
Really though I think that time, patience, and love can do a lot. Especially when you are dealing with someone who is shy and introverted. I don't know if any of this helps. Really I can't see that you have done anything awful. It's life people make mistakes and we don't always know exactly the right way to deal with a new situation. If you have done something wrong apologize any way you feel comfortable and move on. She's young give her time and acceptance. Either she will accept it or she won't. Just hang in there.