As far as I know, there is only one recognized demon goddess in any myth or culture. And that is Lilith, who is associated with both mischief and chaos.
If you're looking for a DEMONIC goddess, or a goddess who is not exactly considered as a demon but somehow demonic in nature, there are plenty. The Greek goddess Eris is usually associated with mischief and discord. The same goes for her Roman counterpart, Discordia.
Chaos, a figure that can be found both in Greek and Egyptian mythology, is a primordial goddess of, well, Chaos. She is the being from which all things took form.
Other goddesses associated with evil:
Enyo, goddess of bloodshed and war
Keres, spirits of violent death
Odyne, goddess of pain