season 7 - Xander drives around collecting Potentials

I have a feeling that this story may be a sequel to a season 6 story in which Spike & Buffy get together, but I can't remember what that one is either.

We follow Xander as he drives across country (in the US) collecting up potentials, or possibly newly activated slayers. He is directed by the gang back home who are doing spells to locate them. He reaches one girl just as her family is killed by bringers, so little sister has to come too - and little sister is a cutie and when they get back to Sunnydale, she steals everyone's hearts.

I've been looking for ages...

I'm reading it just this week: it's the gates of time by authoressnebula.
backward for the part in season 6
setp forward in season 7 with little jillian, so cute!
you can read in on athenewolfe just reward

Thank you!

I was beginning to think I'd dreamed it...

you're welcome
really great one