You can sell them or give them away or throw them out -- you bought them, so you can dispose of them as you wish.
Copyright would only be an issue if you decided to photocopy/scan/photograph/mimeograph the patterns and directions and then distribute those (either for money or for free). If you try to sell many, many kits and patterns, you might trigger the attention of the original author or publisher, and they might contact you -- that has happened in very rare cases. But once you established that you were simply a big fan whose eyes were bigger than her estloe (estimated stitching time left on earth), I can't imagine that there would be any issue.
Well done going through the collection and passing along some goodies for another person to take on. I always find it very freeing to reduce the backlog.