I wonder if you keep her still seperated?!
When we've been to the cat shelter earlier this year they had a small feral girl there, too...she was kept seperated, but she wouldn't bond, because she wasn't used to humans...
One day they've released her into a big cat herd and the lady from the staff accompanied her and it happened that in this unfamilar place the kitten starts looking for something/someone familar...and that was the lady from the staff!!!
Until this day she became more friendly every day accepting the human to be just another cat!

I don't know if that will work with sweet Annie, but I agree with the others that it sometimes takes quite a long time to get through to a freal, even a kitten...they are very sensible and each one is so different, that in some cases it may take some time...

Talk to her often, so that she will get used to your voice and make no attempt to touch her at first, when she responds to your voice start to touch her, so that she gradually loose her fear and work with loads of treats!!!

I do hope you'll find a way to get through to her..GOOD LUCK!!!