Start training her not to by teaching her the word no if you haven't already. Be firm but not aggressive when you say no to her, you don't want to make her feel abandoned by you, it's simple things that can trigger her to think these things. Like Buffy said, get some chew toys in the house, when she goes to lick you say no and present her with a toy. Alternatively you could stretch your hand out in front of her and say it's okay. Threw repetition she will understand that you aren't mad at her for wanting to show you affection, only that you don't need affection all the time. Also, do you show HER too much affection because she was abused? At first it's okay to let he become comfortable and feel safe, but then some ground rules need to be met. Good luck.