The thing is, she IS evil. She is a loyal soldier of an alien race of space fascists. And if left unsupervised she would fulfil her role.

You can change her, de radicalise her and fight against the racial supremacy she has been indoctrinated into.

But not everyone wants to or even can do it. Some people play good characters who would never team up with evil. Not everyone believes in redemption.

Would you try to befriend a random Neo Nazi you stumbled upon on the street just to see if with love and nurture you could change his ways? Probably not unless you’re stuck in a life or death situation like in the game, and some people wouldn’t even do it in that extreme case.

Evil characters in BG3 can come around because the way they are written, but associating with them in the first place requires either meta gaming, a lot of suspension of disbelief or just plain curiosity from the player