Joyce Slayer Buffy half vamp

Joyce was the slayer in love with Sam Lawson. Buffy is their child. Buffy hates the present slayer (Kennedy-I think) Buffy meets Spike, who is curious about a vamp helping a slayer

That's a very good one (the one I think of); I'm always waiting for updates.
It's by maryperk73703 - Is that the one?

Kissin' Cousins by maryperk
Summary: After the events of All the Way, Spike and Buffy stumble across an interesting picture in Joyce's photo album. (WIP)

Link to the fic:

- at her site
- at her LJ
- at EF

There was another one, in that Joyce was killed and Buffy wasn't the slayer - she is in this one. - I searched a bit but I couldn't find it and I don't remember the author.

that one's very good but it is not the one I am searching for.

Joyce was never a Slayer in Kissin' Cousins, and Kennedy isn't in it either. It's set in Season 6.

I know some parts of the story.

Spike said she smells like family. Keenedy left her in an alleyway with Spike after she saved Keenedy. Xander looked at her like she wanted to kill her.

She lives with Wesley. It was a challange reponse.

It's only like two chapters long, WIP, and has not been updated since last year. Come on brain work.

The Quickening by LadyEnchanted has a half-vamp Buffy, not sure it's what you're looking for, though.

Haven't read it do you have a link.

Link:

The Quickening by LadyEnchanted

http://spikeluver.com/SpuffyRealm/viewstory.php?sid=33037&warning=NC-17

Summary: Joyce Summers is a rational and intelligent young woman. However, after a reckless night she's left with more than she thinks she can handle. Pregnant and alone, she leaves everything she knows to lead a new, different life. She gives birth to a daughter, Buffy, who may not be as normal as she seems ...

good but still not it. The one that was mentioned by gopher101 sounds like the right one.