I am in favour of selling it if you don't wear it, maybe keep one or two pieces as a memory and for sentimental reasons, but not everything. Recently I did the same with one yellow gold set (necklace and bracelet) I got ten years ago from my mother-in-law. I never ever wear yellow gold, it was just sitting in a box all this time. Before I did anything, I checked with my husband if he was OK with that, it was a gift from his mom after all.
I went to the jewelry store she originally bought it from, they told me how much it was worth now and I chose a beautiful white gold ring and earrings which I would surely wear. If I had taken the money I would have spent it on God knows what, this way I have the ring and the earrings to remind me of her, instead of that original set which was never my preference anyway and was a bit old fashioned.