I can't find Diedne's (the founder of House Diedne) gender... Was Diedne a he or a she? Logic would tend to go for a male, since Diedne's magic came from druidism, which usually only allows males, right? (I believe it has a female version, but I cannot recall if this is certain ).
Diedne was a woman. Diedne means "to the witch" - and yes druids were not women. More correctly she could be called a wise woman, a priestess or - a witch. Nevertheless she brought scores of druids into the Hermetic Order, thus the majority of the mainly Roman Houses have probably just labelled her a druid for easy reference.
I present almost all knowledge of Diedne to the characters as "hidden lore" which a character would need a good reason to even be asking about. Now the gender is kind of plainly non-harmful, but having the lore as forbidden keeps everything the players know as possibly incorrect and certainly dodgy.
Sorry, I'll clarify : I was actually fishing formoreinfo than the "general gist" of things (like what Diedne's detailed history was, etc.)... Or is it all over the place?
I believe it's left vague, for a saga to flesh out. They are the bogeyman of the Order. And that's the great thing about the Diedne, the renounced House and the Founder.