My wife wants to be able to play NWN:EE online with me, but she doesn't want to create a GOG account just for that. If I buy it as a gift, can I use the key from the second copy, or is there another way to just purchase a second copy with a key?

Thanks.

I'm not 100% sure but I think you only need an e-mail adress to create a GOG account? It shouldn't be a big deal, and if she doesn't want to do it, you could just create one for her (with a throwaway adress or something), then gift the game to her account, log into it yourself, if she wants nothing to do with it, and retreive the key for her (and the DRM-free offline installers, if required).