What I'm saying is that there is an absolute truth to who Shadowheart was right up to the point where we meet her in that pod, and that history informs our initial interactions with her, is the point I'm making. She's always got a set history that is always the same once we get to that pod. And that history and what she's done and who she is when we meet her is what the people who have a problem with her and call her evil are talking about. Saying "well you can change her" isn't satisfying to those people because they take umbridge to who she was and who she is when we meet her. What we influence her towards doesn't change who she's been, the same goes for all the companions. No matter what we do, Wyll will still have made the pact with a devil, always for the same reasons. Astarion will always have been turned into a vampire spawn, Gale will always have tried to usurp Mystra. And it's those things people have a problem with. People look at the things they did in their past and decide "no, I don't want to associate with them because of what they've done and what they are now, and what they, based on their past and current actions will continue to be if I don't take the effort to change them.
And what actions are those? What proof do you have that she was evil? I haven't seen a single list of any actions or reactions she took before meeting you.
Saying she is evil because she seems to be sworn to an evil god is a real slippery slope. There are plenty of human beings that are sworn to a inhumane religious groups here in the real world that aren't evil just because they were brainwashed to think it was right.
Once you meet her however, we do have lists of her actions and reactions and I would to hear your logic for how they on average tend towards evil. Here's a page with a list in case you need it:
https://baldursgate3.wiki.fextralife.com/Shadowheart
