A Shiver of Light by Laurell K Hamilton (2014) Berkley

Merry Gentry, former P.I. and now full-time princess of faerie, is pregnant with triplets.  Taranis, King of Light and Illusion (one of the faerie courts) is suing for visitation rights, claiming that he is the father.  Merry knows she was pregnant when Taranis raped her.  But she can’t prove it.  So she is calling on her guards, and real parents of her unborn children, to face down the high courts of faerie.  A war she does not want to get out of control.