Rice only recently merged the two storylines, in Blackwood farm and more finally in Blood Canticle, which is actually the final book in both series.
Witching Hour actually has two sequels, Lasher and Taltos, which, after reading the end to Witching Hour, you'll want to read.
All her character's arcs are allegedly closed out for good in Blood Canticle. She wants to move on to other things, now that she's spent so many years with vampires and witches.