Oracle's Moon — Thea Harrison

When Grace Andreas's sister, Petra, and her husband are both killed, Grace inherits the Power and responsibilities of the Oracle of Louisville, as well as her sister's two young children--neither of which she is prepared for. Then Khalil, Demonkind and Djinn Prince of House Marid, decides to make himself a part of the household both as guardian and counterpoint to Grace's impudence towards the Elder Races.