Merry Gentry Series by Laurell K Hamilton

Meredith NicEssus, Princess of the Sidhe courts, should have had a dream life. What little girl doesn't dream of being a princess? Unfortunately for Meredith, she not only has royal, but has lesser Fey and human blood flowing through her veins. A combination that left her as mortal as any human being and weaker than most Fey.

Born into culture with a class structure where such small things as blood lines make a very big difference. A life at court, where politics and petty games of arrogance, cruelty, sadism and the occasional assassination, were regular parts of the daily regime and anyone different was fair game. To save her life, knowing that the Court would view it as a betrayal, Meredith fled for the human city of Los Angeles. Adopting the name Merry Gentry and accepting a job with the Grey Detective Agency as a "magical consultant" she tried to keep her past a secret.

Three years of evading Court searches comes to a crashing halt when Meredith investigates a man using magic against humans. There is no way for Meredith to avoid scrutiny or hold her cover. The Queen of Air and Darkness never forgets and never forgives, even for family. Once discovered Merry must trust those she has no reason too. Expecting to be killed, whether it be quick and merciful or long and slow, Merry comes home. But the Queen wants Merry alive for her own reasons. Just as surely as someone else wants her dead for those very same reasons.

Merry's aunt, Andias the Queen of the Unseelie Court has set a contest between her son and Merry. The first to bear an heir will inherit the throne. As Merry beds the Ravens, guardians of the queen, in an attempt to get pregnant before Cel inherits the throne, she and the guards must fight off numerous attempts at assassination. All this and she still has her day job as a private detective at Grey's Detective Agency. No one ever promised being a Fairie Princess would be easy.