I found that my rats kind of bounced off each other, so when one approached me the other one would slowly follow suit. They learned together that I wasn't a big bad scary predator. Once one realises you're a friend it can be easier for other rats to realise the same! How long have you had her? And what's her name?
Update on my Ramona. I have chosen not to follow the rat daddy immersion advice. Instead since I understand that my girl is scared I chose to just move slow with her. Right now I wear gloves, but I can pick her up and she runs up my arm. We are both moving slowly, but I understand. She also LOVES kix and will come out and take them out of my hand. YAY for progress!! Love my little ratty!!