Roxy got me worried for a long time - she was quite a nervous dog and would not allow us to be too friendly with her. Just when you think you can give her a pat on the head, she pulls away! But we did not give up :)
Some days we just sit near her and let her come to us. And talk to her. And sing songs to her... thank goodness no one else hears us! Day after day, you just see her come out of her shell and it's incredibly rewarding for us :D
Then just one day she came up to us and dropped into a play bow and basically said "play with me!" We were so surprised, we just looked at each other and went "did you see that?!" And after that, all was good.
She's wonderful with other dogs, so that was always a fall back option; we would give her human space but kept her with other dogs so she was always socialising. I have a good feeling that when we see Roxy again next time, it will just get better and better .