Good conditioning advice!If you must pick her up, give her a reason to enjoy it. Start with short pets, and follow it with a game, or a tasty treat. Progress to longer touching and even more awesome rewards. You need to change the association before expecting the behavior to change. She is warning you for a reason, and if she hasn't bitten you, it's a good time to resolve why. Growling isn't abnormal behavior, irregardless of the context. She has reason, now find it.
As I read, I wonder, why should she be okay with it?
My last cat never liked to have her tummy rubbed. Under the chin, on the butt, behind the ears...that was all great, but no tummy. I could probably have worked on her until she tolerated it, but why? Why rub her tummy if she hates it?
Alvin doesn't like my new kitchen floor. I used to feed him his dinner in the kitchen and he will go in there if it's to eat, but he's obviously terrified and has even caused himself to fall down a couple of times because he's walking in such a hesitant way. I moved his bowl to a mat in the living room. I could probably figure out the kitchen thing, but why? Why does he need to eat in the kitchen if he doesn't like it?
I guess I have some sympathy for little dogs who don't like to be picked up simply because I imagine I wouldn't like it myself if a very large entity came by and swept me off the floor without my consent. My imagination is notoriously overactive, though, lol.