I agree.....cardboard boxes are the best. I get alot of deliveries (mostly cat food!) but there's always a cardboard box to play in once I open the package.....and my cats know this.

Give her some time. It might take several months but give her a chance. New smells, new noises.....cats have very sensitive noses and ears. Anything "new" will cause her to have to investigate it and determine that its not a threat to her.

I'd start keeping a notebook of what she does each day. Then, in a few months re-read it and see how far she's come!