1. Hellflower (1991)
2. Darktraders (1992)
3. Archangel Blues (1993)
1. Speak Daggers to Her (1994)
2. Book of Moons (1995)
3. The Bowl of Night (1996)
The Twelve Treasures
1. The Empty Crown (SFBC Omnibus Edition of the three "Twelve Treasures" novels)(1997)
2. The Sword of Maiden's Tears (1994)
3. The Cup of Morning Shadows (1995)
4. The Cloak of Night and Daggers (1997)
You can see she didn't finish the twelve, and the omnibus I read is the Bast series.
The protagonist, Bast, is Wiccan. She lives in New York City and lays out books and such. Each book has a murder that's related to Wicca and she's the one who figures them out (I figured them out a bit earlier than Bast). She has a wonderful "voice" and put in things that made me laugh. For example, she lays out a piece for "Flatiron Publishing" and Forge is in the Flatiron Building. She sleekly compares a Wiccan convention to an SFF con. She has Red Zinger and Morning Thunder tea, which I haven't even thought about for years.
The mysteries are engrossing and her descriptions and showing of Wicca is almost hidden, yet you understand what it is. Bast grows and learns during the books, so be sure you read them in this order if you don't get the omnibus.
I highly recommend these (and the other books of hers that I own -- I don't know about the others).