Im still a real goat novice, so I cant really offer any sound advice, but I had the same problem with my Billy. He had always been the shy one and didnt want to be touched or approached, he'd just run away. Then he started to get friendly, even more than Toby. Then one day, he went back to his former self. I was so disheartened as it had taken loads of love and patience to get him to want to be cuddled.
I made the decision to let him get over it by himself. I didnt try to stroke him, I just talked to him.Slowly but surely, he got his confidence back and now he is first in line for a hug and stroke. It was the same with getting them in at night. If they wanted to punish me for something, they would just refuse to go into their house for no reason.
I think what Im trying to say is maybe she is just having a huff and a strop and knows that she can wind you up by misbehaving. Anyway, good luck with her, Im sure she'd soon coming running to you for milking if she was very full. It must be uncomfortable!!
Mary.