fearful

First don't acknowledge her, when she cowers just ignore it.

Then you want to treat her anytime she walks up to a person, or sits still for a person to pet her. If she won't do that yet, just have people throw small treats in her direction, but make sure it's not scaring her. When she gets more comfortable, she can meet more people, she just probably hasn't been socialized yet.

Though I have to say, this is going to be a long term project for you two. But you'd be surprized how much she can change. Read this story about "Mia". Mia, A Rescue Miracle

I agree with what BlackPuppy said- just ignore the dog, drop little treats as you walk by her general direction. You can try sitting in a chair, drop a treat and don't look at her, just drop them closer and closer until she'll take one out of your hand. I wouldn't try petting her yet, let her come to you.

I have a friend from Belfast, wonder if you know him? His name is Anthony McLaughlin

Good point, Stosh, about eye contact. Eye contact is a sign of dominance, so avert your eyes for now.