Has she seen the vet again to make sure something isn't wrong that she doesn't want to be touched and held? Sometimes not wanting contact may have something to do with an illness or injury. It's worth checking with the vet about.

I second that you try the Feliway. The plug-in diffusers would probably be best. Research them so you understand what it is and how to use it properly.

Don't push yourself on the cat but definitely try to take advantage of when she seems relaxed...try to sneak a pet or two in, then give a treat and praise in gentle voice.

You might want to try something like lying on the floor with kibble or treats all around you and let the cat investigate you at her own pace & desires, don't try to touch her, just let her check you out. Do this as often as you can and see if she warms up to you. We "tamed" a scared cat we rescued years ago with this method. In about 2 weeks time the cat was getting on our lap for lovin's.

Mostly, let her be who she is and love her as she is. She can still change as time goes by. My oldest girl, Philly, was always quite independent and aloof, frightful of strangers/visitors. She has changed immensely over the last 6-9 months or so. She is much more social than she used to be and even allows certain people who only visit occasionally to pet her. Took her 5 years, but I love these positive changes in her.