I think they just have individual tastes like we do. Annie loved to be cuddled and petted, Boo too. Gracie Ruth not so much, as a young puppy she just seemed too busy "doing stuff" to be bothered with the whole petting thing. She's 10 months old now and does enjoy it more and actually seeks it out. Yogi is 4 months and although he likes it, he too is more into "doing" then cuddling. The thing I've noticed with Gracie is that she seems to struggle with static, even in the summer time. So I thought that perhaps she could feel static shocks when I stroked her and thus didn't like it. So I changed from stroking her to scratches with my finger tips and that seemed to be about the time she started coming to me for 'pets'. I don't know if that was really the difference or if she just had grown up enough to start enjoying it. But now that winter is here and between my long hair and hers the static is, well, electric in our home.
I try to use a lot of hand lotion and to touch something metal first to discharge any static I have built up. I've reached to pet one before and saw sparks jump from my hand to the tips of their ears.
ahhh, yeah, that doesn't help the whole go to Momma for some good lovin' idea.
Try different ways of 'petting' and maybe you'll come across something that she'll like.