Revealed in Fire by K.F. Breene

Reagan’s trip down to the underworld was never going to remain a mystery. And now Lucifer is actively looking for the woman and her vampire cohort that raised hell in his domain.
When a band of demons come to the surface with a note asking after Lucifer’s heir, the truth of Reagan’s true lineage can no longer be hidden.
The problem is, the elves remember Lucifer’s past heir, and how he nearly took down the Realm. This time, they do not intend to stand by while Lucifer finds his heir and raises her to power. This time, they’ll cut the problem out at the root.
Reagan went from a nobody in NOLA, to the most wanted woman in all the worlds. It’s time for her to own who and what she is. It’s time for her to fight back.