Epona

Epona is a Romano-Celtic goddess of horses, mules, cavalry and fertility. She appears in Battle of Wits as a semi-antagonist and in the Patty Jackson series as a minor character.

History
She was born into the "Tuathe De Dannan" (the Celtic pantheon) but after Gaul was conquered by the Romans the two religions began to mix, similar to what happened when the Greek conquered Egypt. Epona was able to assimilate into the Olympians and she managed to do this without being renamed or marrying any of the Roman gods.

She was the sole Celtic deity to be ultimately worshiped in Rome itself and throughout the empire

Epona's persistent lack of a husband spawned rumors that she had made a vow of eternal maidenhood like Artemis/Diana or Athena/Minerva. But no, the truth is that Epona is just a lesbain.

Personality
Epona's personality is remarkably similar to Percy Jackson.