Lafay /Lafaye (any version thereof) as her last name, fanon or canon?

Her having a past of abuse, mother a drug addict or prostitute and faith whitnessing some disturbing things as a child?  fanon or canon?

I know shes supposed to have had a bad childhood im just trying to get the facts straight , because some of the fanon is so cleverly thoughtout and its so easy to unknowingly fit that in to canon.

Faith Lehane <--canon

As for the rest, I've got no idea.  But good luck finding out. :)

Her last name was never used on the show, but I think Joss came up with Lehane for the comics.  It was only mentioned that her mom was an alcoholic in canon, everything else in fictions is probably just made up.  That's what I love about it, seeing the different things that people create for the characters.

In "Enemies" Faith mentions when her mom was 'so busy enjoying the getting drunk and passing out parts of life' and that she had an unhappy childhood. She mentions being the only kid brave enough to jump off the highest something or other at the quarry to the Mayor, too. In AtS when Faith first comes in the lawyers at Wolfram and Hart address her as Miss Lehane, too, and that's before the comics came out wasn't it? That's all I can think of that mentions Faith's life before she arrived on the show. Some things people inferred from how she acted and her lower-class background. I think it was Marti Noxon who first said that Faith was supposed to be the 'white trash Slayer' and from the other side of the tracks on the commentary for "Faith, Hope, and Trick".

No, she was never referred to as "Miss Lehane" on Angel, just Faith. Lehane is solely from the comics.