I went to High School from 2005 until 2010, and there was this one particular book - which may have been a part of a series.
It featured a red haired young woman who doesn't get her period until she's 20 because she is half human and half (insert race here). This species has golden skin, black eyes and very tall. They also live longer lives-hence her late bloom. Very elf-like, as they can wield magic and so can the protagonist. Her mother chastises her for not being a late bloomer, and she also has a half-brother. I remember he lost his virginity in a whorehouse at like 12 or 13.
There is also really sick antagonist who gets hard over beating women, particularly the red haired female lead. He's pretty bad as he even buys whores that look like the lead so he can beat them to death and get off on it. At one point he uses magic to transfer his soul into her mother's body. The golden skinned people are able to see auras and his is black and red, and she sees his aura around her mother's body.
There are also small grey creatures that can become Gods if they are believed in. Some are inherently omniscient as their power comes from love or war. Whereas others can lose their power if the source of worship decreases - such as a main one who gains power from theft.