maybe a silly question but:

[fox]

I’m almost to the end of my rewatch and it occurs to me: Do we know anything about the Slayer whose death activated Buffy?

Comments

[hannah]

Not from the show. If it's mentioned in para-canon short stories or comics, I haven't been informed of that.

[settiai]

There isn't anything in the series, as far as I remember, but there was a book called The Book of Fours that covered at least some of her story. I don't remember a lot of details, because it's probably been at least a decade since the last time I read it (if not longer), but her name was India Cohen.