Not sure about the timeline for this lore.
I was reading Leiber's books on Nehwon, and the Ice Witch Coven gave me the idea of making a female Nord character that could be similar for role playing.
Then I came across the Witches Coven in Skyrim, but the info I found was sparse.
Anyone know more about this?

well nords seem to have a.. history with witches, so i wouldn't be surprised to see quite a few hidden away in caves. not to mention the one that seems to have a connection of sorts to werewolves (from bloodmoon).

Witch covens were in Daggerfall. I would love to see them return as a guild in Skyrim. But yeah, like Candle Theif says, the Nords have a history with Witches. I think one of their city states was even ruled by one in their recent history.

Jsashe would be gone, but they've got to have some witches in the games. How else are you going to summon daedra lords? You don't want to wait around to do it at the mages guild.

Side note: If there is no reference to naked Nords that were mugged by witches I will be disappointed.