A bit late on this bandwagon, but I saw you all talking about established relationships so I thought I'd add my two cents.

I sort of imagined Lilith as the "anti-social slaughterer" kinda girl. She's been changed so much into this gruesome killer for the Reapers that she really doesn't get out much, if at all. So anything anyone knows of her, information wise, would likely be from fellow Reapers, or if they somehow knew her during her average drug junkie days, before she became a Reaper.

Though, I wouldn't be surprised if a few people knew of her exploits, given she likes to leave her tiger face business card on all her targets. After all, you don't get a name like "The Predator" without a few people noticing.