I wouldn't say the character is evil, but those holy and unholy effects that can perceive sin would certainly read her soul as tainted. I usually interpret evil as "in league with the Infernal," and it sounds like she's not that. But it doesn't sound like she's good, either. I imagine divine agents would be wary of her, and that infernal agents would court her, but that her fate after death is still uncertain.
What does "being evil" mean to you? Do you think she would take advantage of infernal powers if she had them? It would be interesting to see what she'd do with Chthonic Magic. I don't suppose you have access to Realms of Power: The Infernal, do you...?