In Tabletop, I had Shadowheart tell the PCs that she was a cleric of Melira Taralen, a minor elven goddess of bards and minstrels. She was a member of the Seldarine. Although she had no true foes of her own, she was opposed to the drow and goblinoid deities. She had a friendly rivalry with the god Milil due to some similarities with their portfolios. Melira Taralen was Chaotic Good, her symbol was the lute, and she dwelled on the plane of Arborea. She was a lover of poetry and song, and her domains were Knowledge, Life and Trickery.
Shadow then hid her Sharite holy symbol spell focus in the palm of her hand or in her own private pocket, not magic pocket. Her armor was specialty made, but I did not describe holy symbols on it. Later, as time went on, her behavior gave it away, especially her reaction to the shrine in the owlbear cave and then the statue that was broken behind the windmill. The PCs then called her on it.
